Project Blown 305

[Cuttyman9]

I picked up a gmc 305 V6 that I plan to hot rod out a bit.

I was lucky enough to find another in the junkyard to snag some parts from.

My goal: punch out the 305 with aftermarket/custom internals (ideally offset grind down to BBC or SBC rods and use an off the shelf piston for a BBC, if not able to bore it that far use off the shelf BBC Pistons and aftermarket rods with as much stroke as possible)
-Upsize the hole in the rocker arm shaft pedestals, use (BBM BBB or FE full rollers dependent on which is closest to fitting) the shaft size isn't far off.
-build larger shafts for this
-if necessary build new pedestals
-have cam redone for performance and potentially a roller setup(if only defining characteristic is needing to be flat vs banked to work with a roller lifter)
-machine next to lifter bores for link bar
-bush the bores to the correct size for a common engine lifter
-laser cut flanges for the intake to fabricate a steel blower manifold to mount an 8v71 supercharger off an old diesel generator(regardless of if it adds power, it needs to look super mad max-like)
-modify the pan for a deep sump
-build headers using laser cut flanges from thunder v12 (hoping to find magnum heads in the meantime)
-few other ideas but they aren't coming to mind.


My questions:
Does anyone know how thick the bores are? Did they cast one block and bore to desired displacement?
Or did they cast multiple blocks with bore thickness dependent on end displacement?

I ask because if I can I'd like to punch this out as far as I can go (5.125" if possible) and want someone who's had theirs apart and at the machinists testing the cylinder wall thicknesses chime in if possible.

[TJ's GMC]

These engine blocks are All water jacket. From what I have read, .060 over would be tops. There's plenty of bore to begin with anyhow so I'd be looking at stroking as much as possible. If not, find a bigger v6. There's an old story of a guy who hot rodded a 478 v6....made tons of power...more than enough to take on spiced out 454's. And it could handle 5000 rpm. The 478's have a 5.125 bore.

Also...in for the build. Be sure neat for sure. :thumbsup:

[Cuttyman9]

Ah, I wasn't sure. With some engines they leave them thick stock (older Chevy 283s and 352 FE fords) so you could overbore to the larger setup.

I would one to snag a 478 block/crank. Does anyone in northern Cali have one sitting around?

My goal is to put down as much torque as I can under 4500rpm. The Piston speed with the max stroke (ideally 5.18" with a 2.0" rod journal) 4500rpm is max.
It would produce a 644ci if I can use a 5.125" bore and 5.18" stroke.

I want to put a smack down on a lot of the big motors. This has the biggest architecture I've ever seen and 6 bolts per cylinder should allow for a good chunk of boost.

Maybe we can get these motors on the map!
Even hot rod didn't mention these on their forgotten motors article.


I wonder if we could locate that guy who built a modified one

[1972RedNeck]

Ah, I wasn't sure. With some engines they leave them thick stock (older Chevy 283s and 352 FE fords) so you could overbore to the larger setup.

I would one to snag a 478 block/crank. Does anyone in northern Cali have one sitting around?

My goal is to put down as much torque as I can under 4500rpm. The Piston speed with the max stroke (ideally 5.18" with a 2.0" rod journal) 4500rpm is max.
It would produce a 644ci if I can use a 5.125" bore and 5.18" stroke.

I want to put a smack down on a lot of the big motors. This has the biggest architecture I've ever seen and 6 bolts per cylinder should allow for a good chunk of boost.

Maybe we can get these motors on the map!
Even hot rod didn't mention these on their forgotten motors article.

I wonder if we could locate that guy who built a modified one

I like your thinking. I have a plan for a similar build (naturally aspirated) in the near future. My plan is to "only" grind the crank down to BB Mopar rod size (2.375) and then build from there with custom pistons, cam, manifolds, induction, and the like.

Let me know when you start having valve train parts made, I would be willing to double your order which should get us a little better price (maybe).

Actually, if we could work together through the whole thing with identical setups (different cam grind and piston CR would be the only difference), we may be able to get a better price overall, and I wouldn't mind having more expertise than just I can provide.

[Cuttyman9]

Awesome!
Yeah I may be limited in what I can do with this thing but I'd like to know he maximum.

When I sort the rocker system I will definitely post updates.
I need to get a FE/BBB/BBM rockers to see what's similar enough.

Those 3 are relatively cheap to buy a set either eBay for Chinese ones or off summit and you can buy individuals of them which is nice.

Ideally I'd like to just upsize the shaft just enough to open the mounts up and move along with that as it's only .05" larger (.79 to .84 with I believe a mopar rocker)

The lifters are a bit trickier because the spots they sit are pretty filled in so it will take milling the spot between them down and pressing a bushing to match the diameter and make a link bar.

It may be easier to bush the hole, run some inexpensive standard mechanical lifters and a big cam

[Cuttyman9]

With those rods and offset grinding getting to 383 from a v6 would confuse so many lol
Need to have a big v6 badge and 383 badges lol

[1972RedNeck]

With those rods and offset grinding getting to 383 from a v6 would confuse so many lol
Need to have a big v6 badge and 383 badges lol

LOL that would be good - of course a 351M is a big time headsratcher as it is.

Yeah I'm thinking my 478M with offset ground journals (2.811 down to 2.375 plus 3.86 stock stroke = 4.3" stroke) will net me a 538 when bored .030" over. While it might be able to go bigger, the fact that we are shoving all the air through 6 smallish ports (compared to 8 large ports on most big blocks) will just mean the bigger we go, the more low end we have with out much top end benefit.

I'm thinking that 450 to 500 HP and 700+ ft lbs of torque won't take too much to get out of a properly setup 538.:ahhhh:

[Cuttyman9]

I am hoping to have some weird controversial CI to paint on the hood.

I want to use one of the 8v71 style blowers cuz they have a mad max style.

[Cuttyman9]

I agree, that would be awesome. My goal is double the torque output, I was hoping to find some magnum heads to use just cuz even with the 305 and a blower it's gonna require as much flow as I can get.

I really need to track down a 478 out here, that would open up my options for cubic inches so it's not all stroke if the bore cannot be taken to a much greater size.
I guess I'll need to pull everything off the block and take it in. Also cool is all of these are old motors so they are prolly high nickel content which is supposed to be good for this kinda stuff and hard to scuff.


This whole thing is going in my 66 C20 I'm converting to 4x4, I'm in California so they have have those stupid "clean air vehicle" stickers id like to copy and change the wording on and put on the back with the cubic inches next to the blower protruding old nascar style. I need to chase down the GMC V6 emblems for the hood too.

[TJ's GMC]

The 305's are super common down there....so I'd grab a couple blocks and experiment on one with how far you can overbore. I'm speaking from what I have seen more than anything...when I had mine apart with the casting plugs pulled out of the block...it was nothing but huge water jackets between the bore spacing. Thereby somewhat confirming a Huge over bore would either cause premature cylinder failure or you'd hit water real fast. .060 over seems to be the common safe overbore size on most old engines. These things produced pretty decent torque as it is....so a bottom end lightening...more cam....lighter pistons....and some boost will wake them up big time anyhow. If I can't find a 478, eventually I'm planning on rebuilding the 305 somewhat like you are.

[Cuttyman9]

Yeah, it's hard to say really. It's probably me being hopeful haha.

I'm figuring even the 305 stroked out to whatever I can get away with will suffice at that point.

Definitely let me know what you come up with.

Once I get the mopar rocker from a friend to compare with and get time for a junkyard run I'll have an fE rocker to test as well.

[1972RedNeck]

Yeah, it's hard to say really. It's probably me being hopeful haha.

I'm figuring even the 305 stroked out to whatever I can get away with will suffice at that point.

Definitely let me know what you come up with.

Once I get the mopar rocker from a friend to compare with and get time for a junkyard run I'll have an fE rocker to test as well.

If you need a complete FE rocker assembly, let me know. I would gladly donate one to the cause and I have more than a few FE parts laying around.

[TJ's GMC]

Yeah, it's hard to say really. It's probably me being hopeful haha.

I'm figuring even the 305 stroked out to whatever I can get away with will suffice at that point.

Definitely let me know what you come up with.

Once I get the mopar rocker from a friend to compare with and get time for a junkyard run I'll have an fE rocker to test as well.

My build plans so far are pretty much more air flow, compression, and lightening the rotating mass.

.060 over Flat top aluminum pistons that are lighter and 4 ring. 0 decking the block. Shaving the head if I can still get away with .450- .500 lift on the cam...and pending on rocker ratio I'm not sure what that will be on the valve lift so that will have to be calculated. Keeping the total cam duration low so peak power is at 4000 tops.
Opening the head where ever I can....magnum heads for sure with bigger valves. Issue then might be the 4.25 bore may be to small and valves may hit. Rods are beefy enough, but I want to see about taking some weight off the crank and doing more balancing.
Magnum manifold has already been machined for a 4 barrel so I have that done, and then need to make some headers. Hoping for 9.5.1 or 10.0.1 compression. If I can make 340 foot pounds naturally aspirated out of 305 cubic inches I'll be super happy. Can really make an embarrassment out of 350's then. :upyes:

[Cuttyman9]

Yeah that would be awesome on a set of rockers for an FE, 1972redneck I'll try to shoot ya a PM today about it.

Sounds like a solid build! I'm sure you'll make a good chunk of torque.

Thunderv12 sells flanges for exhaust if that's helpful for both magnum and normal exhaust ports.

I may try to get a few sets of intake flanges cut in case others would like to build a manifold as well.

Felpro sells a gasket kit for the 305's on summit, I just recently received mine but haven't opened it.

My machinist out here has done a few of these so that's good news.
I think if I drop in some 60 over flat top Chevy BB Pistons I should be set, then it's just a matter of matching up some rods and stroke it to fit.

Based on info I found online with various sources the deck height is roughly 11.5"


I'll post my findings soon.

[TJ's GMC]

Sounds great, big block pistons and different sized rods would probably be cheaper than going stock with customs.

[Cuttyman9]

Yeah definitely and a load lighter too.
I'm thinking this thing won't be much of a liability overall as everyone claims once it goes on a diet internally.

I'll have the machinist shave as much out of the crank as possible.

[bigblockv6]

Maybe we can get these motors on the map!
Even hot rod didn't mention these on their forgotten motors article.

Years ago(1974) I came across a magazine from around 1960 or 61, it mentioned how the 702 V12 would make a great drag engine. Basically it was an answer column and somebody was looking for something that was different from the rest. I think the magazine was Custom Rodder.

[Cuttyman9]

Ahh, what was cool is mad max remake had a gmc V12 in one of theirs. It kinda led to my friend mentioning how cool one of these would be in my C20.
I was chasing something different and found this had next to no one who had built one.

There has to have been someone experimenting with these somewhere.

I'll try as best I can to make a couple sets of each part so that a few other people can upgrade too or post enough info so it can be recreated.

I'd love for this motor to become a hit and be used more often.
It's such a sturdy platform for power: giant forged crank, oil bath for the cam, insane water pump and oil pump, 6 bolts per cylinder, fully supported lifters, shaft mount rockers.

Just the absence of better intakes, better exhaust, and a lighter rotating assembly make it not so great.

[TJ's GMC]

It's not even that anymore....this new dumb trend is "Buy for cheap, sell for a rip off" or "If it ain't some junk chinese crate 350 that you can get for 2K; it ain't worth nothin."

Seems to be what drives most forums and I'm sick of it. lol People pull out good running v6's and treat them as Junk...yet when one of us Wants it they want over $500! :banghead:

Experimentation has been done, if you look through old threads here in the 09-12 years it seems like a whole roll of people were into making these things perform....but suddenly they seemed to disappear off the map....probably had to have that dumb 350 or Life got in the way....I have no clue. lol
Even on google! I've done tons of research at just about Every forum and lot's of people had great ideas for these in mind...but all the threads just end without anything ever actually Happening.

So be prepared...even with the advantage of having hot rod parts on the market people are still to stinkin cheap to buy them.

My 292 I6 for instance, TONS of hotrod parts on the market for that, yet you still don't see many around! Oh I forgot to mention....it cost more than a cheap junk crate 350 to build a healthy, unique 292. lol

Taste and Unique is going down the drain anymore....shows are really boring when a line of chevy's and GMC's all have the same engine.

What's worse is people are treating SBC like they're something special, when in reality...they are over used and boring as heck. Only thing that interests me is my 572 big block. haha

[Cuttyman9]

I 100 percent agree.

I love being innovative and am shocked that I'm one of the first to attempt this with the full intent and means to make it come together.

I'll have to search the forum a bit, when searching on Google I didn't find much that was finished.

I'm actually in the process of swapping the 3 sbc's I have in cars removed in favor of something far more unique, everyone's point is I can easily do a blah blah for less money that will be faster or whatever.
It's far less about the money, far more about end look/cool and the process of getting there.


My chevelle will be the one that would make any Chevy fan cringe but the 36 Chevy is getting a Nailhead because it's period correct and the truck getting a GMC V6 because they are so cool!


Yeah those I6's are def unusual.
I do see em built now and then. Try looking up Argentina stock car racing. They only race I6's.

I'm very ready for Chevy people to be mad, my chevelle has lit a fire thus far I'm excited to put up giant torque numbers and show why it's better than the 350 Chevy in there. There was one of those 6ms posted for 900 out here like it was gold yet I'm sure they would be first to talk smack. I paid 50 for mine so I was stoked!


I also know people will prolly be slow to throw money out there it's very similar in the celica community. But I figure if I can offer shafts for cheap so people could have their pedestals opened up or if I make new ones. It will all kinda fringe on if it costs me less to make like 5 pairs vs one pair and if it's cheap enough I can sell them relatively quickly.

The rockers could be purchased separate from summit so I wouldn't supply those unless for some reason I can setup as a dealer for Harland sharp or something haha

[1972RedNeck]

It's not even that anymore....this new dumb trend is "Buy for cheap, sell for a rip off" or "If it ain't some junk chinese crate 350 that you can get for 2K; it ain't worth nothin."

Seems to be what drives most forums and I'm sick of it. lol People pull out good running v6's and treat them as Junk...yet when one of us Wants it they want over $500! :banghead:

Experimentation has been done, if you look through old threads here in the 09-12 years it seems like a whole roll of people were into making these things perform....but suddenly they seemed to disappear off the map....probably had to have that dumb 350 or Life got in the way....I have no clue. lol
Even on google! I've done tons of research at just about Every forum and lot's of people had great ideas for these in mind...but all the threads just end without anything ever actually Happening.

So be prepared...even with the advantage of having hot rod parts on the market people are still to stinkin cheap to buy them.

My 292 I6 for instance, TONS of hotrod parts on the market for that, yet you still don't see many around! Oh I forgot to mention....it cost more than a cheap junk crate 350 to build a healthy, unique 292. lol

Taste and Unique is going down the drain anymore....shows are really boring when a line of chevy's and GMC's all have the same engine.

What's worse is people are treating SBC like they're something special, when in reality...they are over used and boring as heck. Only thing that interests me is my 572 big block. haha

I think we would get along quite well.

[1972RedNeck]

I 100 percent agree.

I love being innovative and am shocked that I'm one of the first to attempt this with the full intent and means to make it come together.

I also know people will prolly be slow to throw money out there it's very similar in the celica community. But I figure if I can offer shafts for cheap so people could have their pedestals opened up or if I make new ones. It will all kinda fringe on if it costs me less to make like 5 pairs vs one pair and if it's cheap enough I can sell them relatively quickly.

The rockers could be purchased separate from summit so I wouldn't supply those unless for some reason I can setup as a dealer for Harland sharp or something haha

I wish we lived a bit closer as it would be good to find a great machinist we could both use and sit down over a couple of beers and hash out some definite plans and maybe even pool some funds to make this happen.

[TJ's GMC]

Whatever you come up with keep us posted, Will be one of your customers for sure in the future. lol It'll be a few years before I do my 305 again. But yeah, the 292 in my 66 with make around 310 hp and 340 torque and it's backed by a tko600 5 speed. Will make a great cruiser and tackle some sbc's if I want to. haha

[Cuttyman9]

I know right? Everyone's always so far away but I'm sure the smaller parts can shipped pretty easily.


Definitely will post all of my progress.

I may just model the whole rocker system in cad do I have a starting point.


Sounds like a healthy I6! Prolly going to be a blast with the tko

[TJ's GMC]

72redneck...We probably would. haha


Yeah it should be fun with that trans....3800 pound truck with 3.73 gearing and a close ratio trans should make for some easy burnouts and quick shifting. Plus the way I built the engine it should peak torque around 2500 so it'll be perfect.

[Cuttyman9]

Here's all the info I gathered so far.

Some of it does conflict a bit.


Valve spring
installed height=2.141"
Od 1.367"
Wire od=.0188

Lifter
2.317" tall
0.988" od

Pushrod
7 13/16" long

Shaft
17 7/8"
0.791" od
0.496 id
Multiple 0.1" oil holes
0.335" hole at each end

2 bolt pedestal
2.233" tall
0.385 bolt hole
0.972 hole to hole min
1.119 shaft hole to base
0.791 shafthole

One bolt pedestal
0.147 from small from top to flat
Depth of 0.814"
0.84 from oil hole to round face
Roundface to flat 0.112
0.166 offset boot hole to oil hole

Rocker
2.719" tip to tip
1" thick



Valley cover
19"

Rockers
Width=1.01"
Hole od=0.789"
Distance between= 3.3"
Cap width=1.226"
2.75" length


73-up
28" between rails(inside of C)


702 v12
-3.124" mains (thunderV12.com)
-1.6" pins
-~7" rods
^last two are from (http://www.bangshift.com/forum/forum/bangshift/general-discussion/13963-478-cu-in-v6/page2)

Confirmed 1.24" OD wrist pins
2.811 rod journal
^http://www.bangshift.com/forum/forum/bangshift/general-discussion/13963-478-cu-in-v6

-Exhaust Valves
New Old Replacement Stock (NORS) made in USA by TRW.
* Head Dia 1-53/64
* Stem Length 5-13/16
* Stem Dia .434
* Type Grooved
* Seat Angle 45°
TRW SC2330N
GM 2383318
^ebay listing 221603150615

Melling exhaust valve
* Head Diameter: 1.565
Oriellys V0580

Intake valve guide
* Vintage
* Standard Size
* 0.342 Inch I.D.
* 2.75 Inch Overall Length
* Guide Type: Plain
* Inside Diameter (In): 0.342 Inch
* Inside Diameter (mm): 8.687
* Outside Diameter (In): 0.502
* Outside Diameter (mm): 12.751
Oriellys VG5037

Pushrod
* 7.989 Inch Overall Length
Oreillys RP3099

Pushrod
* Diameter (In): 5/16 Inch
* Length (In): 7.645 Inch
Oreillys MPR121





211-2036*CLEVITE intake valve
fits GMC:
351cid v6, 1964-1967, Diesel*Engines, 2.260" Head Diameter
351cid v6,*1966-1969,*2.260" Head Diameter
401cid v6,*1966-1972,*2.260" Head Diameter
432cid v6,*1973-1974,*2.260" Head Diameter
^ebay listing 371009149096

-Intake valve-
* Head Dia 2.160
* Stem Length 5.849
* Stem Dia .3725
* Seat Angle 30°
* Sealed Power V1563
^Ebay listing 221587715714

Intake valve (305)
* Head Dia 2
* Stem Length 5-13/16
* Stem Dia .341
* Seat Angle 30°
* Type Lock Grooved
* TRW V2327
* RMC V3257
OEM GMC 2368098
^ebay listing 321679596667

2474281 pn rod 478
^eBay listing 282243468585

Con Rod Bearings
6200CP
0.020" / .50mm*Con Rod Bearings
OD 3.016"
ID 2.8117"
Length .935"
Wall Thickness .1010/.1015"
^ebay listing 321887078220

"New old stock piston set for GM 351 V6 truck engine from the 60's. *Includes 6 pistons and pins, ring set and pin clips. *
4 9/16 bore,
approx 2 9/16 comp. height,
approx 1 1/4 pins. *
Parts are in good condition."

^ebay listing 322341673092

[TJ's GMC]

Found this for ya:

"Heres a little about these motors I leared back in the mid 80's. My grand father gave me his 1965 GMC 1t 4x4 that came with the gas 351c v6. I rembered from a kid that this old truck would out pull anthing and never broke down. The old 351 was getting tired with about 200k on it so i decided to rebuild it and of coarse hop it up. So I started looking into performance imfo on these motors. That put me in contact with Babe Erson. He told me about the gas 478M motor and how with some work the big 478m v6 will easily make more tork and hp than a mildly built 454bbc. So I bougth a 478m motor from the junk yard and went to work per Babe's rec's. The first thing was to throw away the stock 4 ring pistons and masive rods that weight about the same as a complete hemi motor. I had a crank grinder turn the rod journals down to a much smaller size to fit a 426 hemi rod. I had BRC make some new lighter 3 ring pistons that also raised the cr up from 6.5 to 9.0. Engine dynamitics lightened the crankshaft alot and rebalanced every thing for me. Babe made me a special cam and all the vale train parts. I ported the heads and polished the combustion chambers myself. I also made a sheetmetal cross ram intake with 1 850cfm Q Jet carb and a set of home made 1 3/4" headers. Once I got all the tuning done on this motor it was one tork animal that would rev easily to 5.5k. It broke the transfer case right away so I put in a beffier transfer case out of a newer ford truck I think then I blow the old gmc rear end so I upgraded it to a dana 70 with posi. I also upgraded the old truck 4 speed to a newer 5 speed that could be shifted much faster. I had put big 38" tires on this truck and could smoke them in 2nd gear. It did not do to bad on fuel also at about 12 mpg fully loaded with a 10ft camper and pulling a 30ft inclosed trailer running about 65mph. I wish I know where this truck (James) is today as I would try to get him back."

[Cuttyman9]

**** that's awesome!

I'm hoping I can make that happen!

Maybe I should contact them to see what they say about the motor and give me a better place to start maybe advice on how they were successful.

I'd love to find a 478 block and crank to work with cuz that would bump the size further.

[TJ's GMC]

**** that's awesome!

I'm hoping I can make that happen!

Maybe I should contact them to see what they say about the motor and give me a better place to start maybe advice on how they were successful.

I'd love to find a 478 block and crank to work with cuz that would bump the size further.

I got this off of another forum, but here is the link. Not sure if he's around much or not. haha Subscribed but lost interest there.

http://www.jalopyjournal.com/forum/threads/gmc-305-v6-the-baby-of-the-series.153130/


Post #22 is the one. Don't mind the ignorance of the majority. lol

[atomman]

I have an intake for for a blower that was flame cut and needs to be welded together. PM me if interested. I was going to use it on a V-12, that is all machined, I have on the shelf, but it will need two blowers.:poke:
Atomman

[bigblockv6]

Just remember that the V12 has different intake manifolds due to spacing and they will not interchange with the V6:lolsmack2:

[atomman]

That is an issue with the magnum heads. Correct?
Atomman

[bigblockv6]

No:pullinghairout: That is an issue regardless of heads:ahhhh: You simply can't use V6 intake manifolds on the V12 nor can you use V12 intake manifolds on the V6.

[TJ's GMC]

Found a blower off a 6-71.....might be to small though. :teehee:

https://medford.craigslist.org/pts/5946781139.html

[Cuttyman9]

Nice! I'm hoping my neighbor will sell me the 8v71 he has for a reasonable priced that one was pretty expensive.

If the intake is close I wouldn't mind modifying it to work I'm just curious what it looks like.

[Cuttyman9]

http://i1307.photobucket.com/albums/s589/cuttyman9/9A3382D2-86D9-4AC2-8580-CD07972418FD_zpsiwwsds6t.jpg (http://s1307.photobucket.com/user/cuttyman9/media/9A3382D2-86D9-4AC2-8580-CD07972418FD_zpsiwwsds6t.jpg.html)

Thanks to Atomman I now am a little bit closer to getting this project off the ground!
Now I just have to wait for it to arrive and figure out which blower I need!

Very excited!

[bigblockv6]

That looks fantastic:welldone:

[TJ's GMC]

:thumbsup:

[Cuttyman9]

Thank you, now having compared to the 6v92 my neighbor has it looks like I'm going to need an 8v71 or 8-71 minimum.

They sell adapter plates for the V style on a normal flange so I may get that since i can avoid trying to drill the angled holes myself and I can drill for a convention 8-71 and be able to swap between em.

We shall see, I'd like to not have too terribly much into making a blower work since you can buy them new/used with a lot of the parts I'd need out of the box.
(Front part with the snout for the pulleys, rear cover etc)

[Cuttyman9]

So here's my plan.

I found a few eBay sellers with blower parts for very reasonable prices

I'll need the blower front cover, the blower rear cover, the snout, the pulleys (which I'll probably buy two to start mock up with them change later) and the adapter to go to the 8v71.
So far I've purchased the adapter, this is already drilled for the angled bolts and includes studs gaskets etc.
I mocked up the stuff a bit.
I'm contemplating cutting off the whole water pump setup to save space and run an external pump, it wouldn't be hard as the pump is cast into the front cover and I'd just need two block off plates to cover the holes and put AN fittings up to them or a spot to clamp a hose. This would also allow me to run only the crank pulley for the alternator (too bad I didn't get the magneto lol)

Turns out they sell new old stock 8v92 blowers for about 600 so I'm hoping that will bolt up the same way the 8v71 does as far as I can tell the engines underneath are the real variance not the blower itself.

Here's the parts needed:
http://i1307.photobucket.com/albums/s589/cuttyman9/300D224F-814E-4F95-BC3B-6A41AD518764_zpsdqwhi2oe.png (http://s1307.photobucket.com/user/cuttyman9/media/300D224F-814E-4F95-BC3B-6A41AD518764_zpsdqwhi2oe.png.html)

http://i1307.photobucket.com/albums/s589/cuttyman9/F25C34D7-8175-45B4-A21D-03AECC133902_zpsifyzikdf.png (http://s1307.photobucket.com/user/cuttyman9/media/F25C34D7-8175-45B4-A21D-03AECC133902_zpsifyzikdf.png.html)

http://i1307.photobucket.com/albums/s589/cuttyman9/07D06085-D9A5-45D1-A5B8-BBC9CF1E164D_zpsdg0icmiu.png (http://s1307.photobucket.com/user/cuttyman9/media/07D06085-D9A5-45D1-A5B8-BBC9CF1E164D_zpsdg0icmiu.png.html)

http://i1307.photobucket.com/albums/s589/cuttyman9/91F03BCD-5CE4-49EB-9D4A-CE27034B6069_zpskufetzfi.png (http://s1307.photobucket.com/user/cuttyman9/media/91F03BCD-5CE4-49EB-9D4A-CE27034B6069_zpskufetzfi.png.html)

http://i1307.photobucket.com/albums/s589/cuttyman9/D1C6DDA6-D34E-418C-AA1F-6A5864D9A058_zpskpwkajfb.png (http://s1307.photobucket.com/user/cuttyman9/media/D1C6DDA6-D34E-418C-AA1F-6A5864D9A058_zpskpwkajfb.png.html)

[Cuttyman9]

Here's the not-so-official mock up:

http://i1307.photobucket.com/albums/s589/cuttyman9/4441504B-B37B-42ED-BD4A-2E9453669A55_zpse12l2asr.jpg (http://s1307.photobucket.com/user/cuttyman9/media/4441504B-B37B-42ED-BD4A-2E9453669A55_zpse12l2asr.jpg.html)

http://i1307.photobucket.com/albums/s589/cuttyman9/2C66A814-AB18-4F2E-9B1B-D1D1049C4505_zpstlj9skzj.jpg (http://s1307.photobucket.com/user/cuttyman9/media/2C66A814-AB18-4F2E-9B1B-D1D1049C4505_zpstlj9skzj.jpg.html)

http://i1307.photobucket.com/albums/s589/cuttyman9/2853F2A9-25A4-43B2-96FF-735ECE947A02_zpscgxb96d3.jpg (http://s1307.photobucket.com/user/cuttyman9/media/2853F2A9-25A4-43B2-96FF-735ECE947A02_zpscgxb96d3.jpg.html)

http://i1307.photobucket.com/albums/s589/cuttyman9/37A7A1A8-44FF-4575-87B4-88327B99881C_zpsyxly5yzu.jpg (http://s1307.photobucket.com/user/cuttyman9/media/37A7A1A8-44FF-4575-87B4-88327B99881C_zpsyxly5yzu.jpg.html)

http://i1307.photobucket.com/albums/s589/cuttyman9/D5694AF3-DE0D-4E9D-8944-05FB4D7AE827_zpszm8kyv34.jpg (http://s1307.photobucket.com/user/cuttyman9/media/D5694AF3-DE0D-4E9D-8944-05FB4D7AE827_zpszm8kyv34.jpg.html)

http://i1307.photobucket.com/albums/s589/cuttyman9/1A6263E6-79B3-4F89-96A9-7DA951D9CDD9_zpspouveo4k.jpg (http://s1307.photobucket.com/user/cuttyman9/media/1A6263E6-79B3-4F89-96A9-7DA951D9CDD9_zpspouveo4k.jpg.html)

http://i1307.photobucket.com/albums/s589/cuttyman9/73F9F7C2-E322-4B0D-8522-4628CD62A497_zpshzf1ifxc.jpg (http://s1307.photobucket.com/user/cuttyman9/media/73F9F7C2-E322-4B0D-8522-4628CD62A497_zpshzf1ifxc.jpg.html)

Excuse the water everywhere but it looks quite promising.

I've found a few places selling tubing that would actually just plop into place so I may just do that although moving the blower up might be cooler too.

It looks promising, the adapter is on its way and I'll be buying a blower tomorrow and the front cover.
What's cool about the adapter is it will work perfect as a template to drill the big steel chunk so I can just bolt it down and not worry about the angled bolt holes that would almost require a machinist to do.

By running an 8v92/71 I should bridge some of that gap (11" from the front of that plate to the crank balancer flange lol) they offer up to an 8" long snout so I should be able to make this work.


Meanwhile my friend donated these to the cause haha
http://i1307.photobucket.com/albums/s589/cuttyman9/00E3EE33-633C-4BC5-91DB-F6840873202B_zpsd22qlhw3.jpg (http://s1307.photobucket.com/user/cuttyman9/media/00E3EE33-633C-4BC5-91DB-F6840873202B_zpsd22qlhw3.jpg.html)

http://i1307.photobucket.com/albums/s589/cuttyman9/A8AB7B96-834B-49BC-94B6-7BF195EEBB5C_zpsibuzjggq.jpg (http://s1307.photobucket.com/user/cuttyman9/media/A8AB7B96-834B-49BC-94B6-7BF195EEBB5C_zpsibuzjggq.jpg.html)

Needless to say, this is exciting.

Kind of tempted to find a 478 diesel or gas block/crank to make it that much more insane and also allow me to get started on the machine work.

[Cuttyman9]

Might have to add to my list...

-478 block/crank somewhere nearby
-Scoop of some kind to match up with two carbs

[TJ's GMC]

Cool stuff man! Perrty excited here to, that's gonna be sweet! :upyes:

[AZKen]

You are building a "Hot Rod"? Wonder why the drag racers never used the 305? Wonder why they never put a blower on one? Hmmmmm. I wonder if it's because they are so heavy? Or if they won't rev. If they were not built to rev? If they would "blow up" with a blower? I just wonder. Maybe they are good for just hauling like all the ads say. Don't know. Good questions though. Trying to completely redesign a motor is possibly a huge waste of time and money. If a person wants a hot rod motor, they are already talking Chevy. So why stay with original if it's no longer an original 305? Are you building a Chevy inside a GMC? That won't work. There will be no "HOT" in your hot rod. A Chevy 350 with minor upgrades will blow your tailgate off. You are talking more torque. Torque without revs will not produce horsepower....as in: hot rod horsepower.

[Cuttyman9]

People usually don't go after certain engines because if the application it's used in is not common for being hopped up people usually don't build aftermarket parts regardless of the merit of the engines.
Typically the most often hot rodded stuff is what's most readily available which would come down to chevys and hondas. Coincidentally the owners happen to be typically the most sensitive. Wonder if there's a correlation.
I'd bet you'd love what I'm putting in my chevelle, anyways, I digress.

The common hot rodded engines aren't picked because of design it's because of ease/cost of attaining them.

At the end of the day if this thing runs and looks pretty (which there's no way it won't with an 8v92 on top lol) I'm content, to me it will be far better than any Chevy product could ever be no matter the output.

[TJ's GMC]

Love'd yer comment Cuttyman,

Diesel engines don't rev, yet a 5.9 liter 12 valve cummins is easily capable of putting out 1500+ torque and 800+ HP all under 3,000 RPM. And that is with a boat anchor bottom end and heavy pistons. Yes, it has a slight cubic inch advantage.....but he only mentioned Revs. And an 8000 RPM 350 would have no stinkin chance. lol

So, someone please explain to me why a v6 wouldn't respond the same way? YES I know...this is Gas and not diesel....But:

A turbo charged 292 on 10 PSI puts out over 350 HP and 450 Torque. Different engine design, but in the Long run....quite similar.....a Truck engine.

Now, considering the 305 v6 is low compression, Adding compression would be a way to make power without the need for more revs. Not to mention you are going to be putting in lighter pistons and lightening up the crank which would easily allow for more top end!

Back to that read up of the guy who hotrodded that 478! It would toast 454's and was capable of 5500 RPM! SO, how come the 305 isn't capable of toasting a 350???

Any engine can be improved, already it's well known that a 500 cfm 2 barrel and dual exhaust is a nice improvement......so a few pounds of boost won't hurt a thing.

Cuttyman, how much boost will that supercharger put out?

[Cuttyman9]

I don't really have a goal output for the SC, probably just 5psi to start and see how well it works.

Kinda depends on a few factors cuz if the bores aren't in too bad a shape I may try to clean it up and run it stock on boost to see what it can do/handle.

If all else fails I'll grab another and start over.

http://i1307.photobucket.com/albums/s589/cuttyman9/098FDF9E-30A2-441F-8142-AAFE8B62E265_zpsjpphq0cm.jpg (http://s1307.photobucket.com/user/cuttyman9/media/098FDF9E-30A2-441F-8142-AAFE8B62E265_zpsjpphq0cm.jpg.html)
Here's what's coming out once the v6 is ready.

http://i1307.photobucket.com/albums/s589/cuttyman9/FA53602C-06C4-4D1C-B283-C5520E7CF07E_zps2rbo0rnw.jpg (http://s1307.photobucket.com/user/cuttyman9/media/FA53602C-06C4-4D1C-B283-C5520E7CF07E_zps2rbo0rnw.jpg.html)
Here's the trucks clean side lol

http://i1307.photobucket.com/albums/s589/cuttyman9/34B054AF-F602-46BE-95E9-A052299EBCB3_zps3ezfzorz.jpg (http://s1307.photobucket.com/user/cuttyman9/media/34B054AF-F602-46BE-95E9-A052299EBCB3_zps3ezfzorz.jpg.html)
And the other side.
I'm hoping the blower won't be forward enough to require me to remove the 56 Chevy hood emblem.

http://i1307.photobucket.com/albums/s589/cuttyman9/742A90C0-68E7-450D-8105-57768825F65D_zpsgppytxnv.jpg (http://s1307.photobucket.com/user/cuttyman9/media/742A90C0-68E7-450D-8105-57768825F65D_zpsgppytxnv.jpg.html)

Planning to keep the exhaust like this but more than likely I'll upsize the rest of the tubing (2.5" straight from the long tubes)

[AZKen]

You kids have fun now. Don't eat too much ice cream. Chat it up some more, it's cute.

[Cuttyman9]

I agree. I'm going to aim for 50 percent underdriven as I'm still learning the ins and outs of these big blowers.
When I get the whole thing together and it runs smooth I might try pushing it a bit more.

When i get to a fully built setup I'll try for more to see what it can do. The joy of the big blower is I can spin it slow and still make a good amount of boost.

Either way I stoked. The blower is on its way as is the front plate and adapter.


Also I'll probably still the main plate for the same pattern as the top of the blower so I can plop the dual quads on for a startup setup so I can get it running without the complications of the blower.

[TJ's GMC]

I agree. I'm going to aim for 50 percent underdriven as I'm still learning the ins and outs of these big blowers.
When I get the whole thing together and it runs smooth I might try pushing it a bit more.

When i get to a fully built setup I'll try for more to see what it can do. The joy of the big blower is I can spin it slow and still make a good amount of boost.

Either way I stoked. The blower is on its way as is the front plate and adapter.


Also I'll probably still the main plate for the same pattern as the top of the blower so I can plop the dual quads on for a startup setup so I can get it running without the complications of the blower.

What are you gonna use for the dual quad setup?

[turbobill]

It's too bad that this thread is starting to degenerate.

Everyone has a point, however it boils down to what each individual wants out of what they are building. There is nothing wrong with a high reving small block NOR is there anything wrong with a boosted low speed engine, gasoline or diesel.

Over the years, I've done it about every way it can be done, but my favorite is boost. I've boosted sixes up to big block V8's and I've fooled with the diesels too. As my first turbocharged engine was in 1976, that's where my preference lies. Does that make me right or wrong? NO. It's what I prefer.

I love the idea of a supercharged 305. I also like high speed small blocks. One is no more right or wrong than the other. It's what the owner builder wants, not what someone else thinks is right in their eyes.

On the subject of GMC blowers, the 8V92 blower moves about 736 cubic inches of air every revolution. For every other GMC blower, multiply the first number by the second and it will give you the approximate airflow per revolution. Your 305 will breath 152.5 cubic inches per revolution (at 100% VE), so figuring out which blower at what drive ratio is easy depending on your boost requirements.

Personally, I think it is a neat project!

[Cuttyman9]

Yeah, to be honest until one dude popped up I felt this was one of the best mod useful forums.

Im from the same thought process. Anything can make power, it's more a matter of withstanding the forces applied.

I'm going to say at 50% under I should be making a decent amount of boost. I get different answers each time I search on specific blower info. Some say 8v92 was the cubic inches of the diesel it came on and the 8v71 was the same blower almost but mounted to a different engine id noting slight mounting changes(I hear its taller than the 71 due to the top flange being taller) but overall flowing the same amount and having roughly the same case dimensions.

I'm excited for this, I'm glad there's a few others who are as well. This group overall has only made me more excited as it's pushed me closer to my goal.

[Cuttyman9]

Whoops double post.

I'll snap pics when I get the blower here.

Definitely excited for that!


So since I ordered an adapter for the top to fit on the steel plate I have I'm thinking I can drill 6 holes to mount the dual quad plate directly on that to run NA first, then when the motor is sorted I can slap the blower on, move that plate up to on top of the blower and off I go.

https://www.ebay.com/itm/181486211512

[Cuttyman9]

If anyone's chasing these parts to do your own it's all on eBay through a few vendors.

The running total will prolly be under 1500 for the blower related stuff which I feel is really good.
I'm waiting for the next swap meet to find a test belt and gears.

[TJ's GMC]

Yeah, to be honest until one dude popped up I felt this was one of the best mod useful forums.


There used to be two, one was finally banned. Yer gonna get those folks who think that what they say without proof actually matters. Both told me that the 4 barrel mod I did was a big waste of time and that I was dumb and ignorant for doing so because...Oh that math says blah blah blah....Who gives a darn? REALITY says it works and works well. lol

Anyhow, $1500 for boost ain't a bad start! :thumbsup:

[Cuttyman9]

Yeah, some people just really only think an SBC is all that works...

It's kinda a shame we don't have a company that produces the flanges cuz we could prolly easily make a nice 4 barrel intake that takes a bit more advantage of flow with a more stand up intake.

It's a shame it would take a lot to convince edelbrock or someone to create the part.
A simple 4 barrel medium rise intake would bump performance and also offer better fuel mileage since a big 2 barrel doesn't have a small set of primaries to do the low speed stuff.

Yeah I don't think it's bad at all.


I did a bit more searching. 8v92 was the diesel it was under, the 92 was the cubic inches per cylinder equating to 736 ci. The blower is needed because it's a two stroke and it doesn't make enough compression or something
I'm going to need to find more info on how much air the blower pushes at a specific rpm so I can somewhat calculate the psi of boost.

[turbobill]

I did a bit more searching. 8v92 was the diesel it was under, the 92 was the cubic inches per cylinder equating to 736 ci. The blower is needed because it's a two stroke and it doesn't make enough compression or something
I'm going to need to find more info on how much air the blower pushes at a specific rpm so I can somewhat calculate the psi of boost.

Detroit Diesel's nomenclature is the first number is the number of cylinders and the second number is the displacement in cubic inches per cylinder. Where a "V" is between the two numbers indicates it is a V type engine.

As these particular Detroits are two strokes, they aspirate every revolution. The reason for the blower in the first place is not for any supercharging, but to aspirate the engine as a two stroke does not have a dedicated intake stroke. Pressure to charge the cylinder must come from an outside pump.

The 2 stroke Detroits have been around since the late 1930's, so it didn't take very long for someone to figure out their blowers would make great air pumps to supercharge 4 cycle engines.

You really aren't going to need an 8V92 blower to pump up the 305. A 6-71, 4-71 or even a 6V53 would do the job. The smaller the blower, the faster you will have to turn it for any given amount of boost on your 305.

A few things to remember about the GMC blowers. The bigger they are, the more power they'll need to turn. Also, for any particular blower, the faster you turn it, the more power they absorb. (double blower speed, and the power requirement increases about 4 times depending on the internal leakage) Also, the GMC blowers become less efficient as you try to extract more boost from them.

I'm thinking a 4-71 (284 CI) or a 6-71 (426 CI) blower will give you the boost you want without absorbing to much power or becoming less efficient. Not to mention they are smaller and will probably package better on a narrow/shorter engine like the V6.

B&M used to make a couple of blowers, one was I believe 144 cubic inches for mildly boosted 350 sized engines and the other was a 177 incher for mild big block sized engines. Both of those were of smaller capacity than even a 4-53 GMC blower (212 CI) and they were of a nice small size easy to fit in most applications.

In theory, a blower providing 305 cubic inches of air per revolution directly driven at crankshaft speed would make 15 pounds of boost on a 305 cubic inch 4 cycle engine. In reality, the charge heating would probably reduce intake charge density to the equivalent of about 8 pounds of boost. If I recall, the maximum efficiency of the GMC roots blower is about 45 percent.

Between your engine size and boost desired, for any given blower size, you'll be able to easily calculate the needed drive ratio. I'm sure there is plenty of information and probably graphs of the various outputs of the many blowers out there, including the GMC's.

[Cuttyman9]

Thanks turbobill

The harder part seems to be finding info for non 71 style blowers in terms of cfm and displacement.
I don't believe the 8v71 and 8v92 are different blower wise but are from the diesel they came off of but I'm having trouble finding anything on the blower itself. As for what I should use, the 8v92 is already on its way and is new so I'm sticking with it.

Something to note, I may have a handle on 2 478's and a 401 so I may be stepping up the cubes in that way.
JE said they can produce a 5.125" piston so then I'd just need to machine the crank to fit a rod that matches a decent compression height.

[turbobill]

If the 8V92 and 8V71 blowers turn out to be the same, in your search for info, you will probably find that it is driven faster on the 8V92 engine. I'm sure there is a Detroit Diesel forum out there for the guys that love 'em. Such a forum may also be linked to an page for old GMC trucks and buses. The Antique Historical Truck Society forum has a few guys that know the old Detroits well, so maybe they can tell you.

Scour ebay for old Detroit service manuals for both the 71 series and the 92 series. They may also have the tech info you're looking for. I have one from my military days, but it is buried somewhere lol, and it was on the 71 series. That was before the 92's came out.

I have a 478 that I'm going to boost with a turbo. That particular truck currently has a turbocharged 468 Chevy big block, but I've always wanted a 478 for it. Took well over 10 years to find a nice one and I've had it now 17 years so I need to get started. Retirement is less than two years away fortunately.

Also laying around is a 478 Toro-Flow and a few 305's. At least one of those will eventually wear a turbo too. (maybe both) Don't know what I'll use them in as I already have over 20 vehicles and really don't need any more lol. Guess I could always put them on display and run 'em now and then!

[Cuttyman9]

Haha nice!

I'm curious the differences in block and internals on the diesel 478's.

I'm only stating that as that's all I've found differentiating the -92 vs -71.... some say it's bigger bearings etc.
I would agree there's probably a bump in speed that the blower is spun at.
I haven't dug through the diesel forums because differentiating between the blower they use and the engine itself is difficult based on the blowers not having a name/number themselves.

[Cuttyman9]

And I know the feeling, I'm at 9 vehicles... all projects (either because I turned them into a project or they started that way) at 28 so I def understand the thought there haha.

[turbobill]

The block is a bit different on the Toro-Flow as it has a balance shaft on the left side just above the oil pan rail and the assorted gear train to turn it.

I believe the rod/main bearings are the same size between both and the cylinder head bolt pattern is also the same. The bellhousing and rear of the engine looks the same.

Some gaskets are the same and I wouldn't be surprised to find the rods and some of the valve train may be the same too.

[Cuttyman9]

Interesting, I wonder why they have a balance shaft if it's the same everywhere else?

I wonder if the block was reinforced further than the gas variants?

Would be neat to investigate.

[turbobill]

I doubt I'll have both of mine apart at the same time so I won't be able to help lol. I wouldn't dare pull the heads of the Toro-Flow as I have yet to see any available anywhere.

[bigblockv6]

Interesting, I wonder why they have a balance shaft if it's the same everywhere else?

I wonder if the block was reinforced further than the gas variants?

Would be neat to investigate.

The ToroFlow engines did use crossbolt mains, so they were a 4 bolt main vs 2 bolt main for gas engines. In 1973 GMC had redesigned the bottom end of the block only on 478M gas engines with much larger main journals as well as more beef in the main saddle area and much larger main caps & bolts but still a 2 bolt main. When I get a chance I'll take some pics of the newer main caps vs the older main caps and post it.

[Cuttyman9]

That would be awesome, the mains in these aren't too terribly large from what I've seen.

I almost think a big diesel block would be a good foundation if not better than the rest since it's setup for 4 bolt mains although I don't plan to rev this hard, just make the blower work early and stop at 4K.
The hard part will be making the truck work on the freeway unless I adapt an nv4500.

[bigblockv6]

I think you'll be fine up to 4000 rpms, sounds like a fun project and you're doing something that nobody has attempted:thumbsup:, pay no attention to the nay sayers:notrolls:

[Cuttyman9]

Thank you! I'm very excited about it.
I'm hoping I can come up with a way to grab the 478's and toss one in for the time being and sell the 305 to build the other.

I'll have a bunch more coming very soon when the blower shows up with the adapter plate and front cover!

[bigblockv6]

If you toss in a 478 just know you have to have the correct 8 bolt flywheel that has offset weight on it since these are externally balanced engines. A 401 may be a better choice, most 401's will accept the 305 flywheel as long as they don't have the 8 bolt crank flange.:thumbsup:

[Cuttyman9]

Didn't know that, maybe I'll start with the 401 then and build on both of the 478's haha.

Weird they would go internal and external balance on the different sized engines of the same family

[turbobill]

The 478 has a longer stroke than the other V6's, hence the reason for external balance in this case.

[turbobill]

That would be awesome, the mains in these aren't too terribly large from what I've seen.

I almost think a big diesel block would be a good foundation if not better than the rest since it's setup for 4 bolt mains although I don't plan to rev this hard, just make the blower work early and stop at 4K.
The hard part will be making the truck work on the freeway unless I adapt an nv4500.

I see no reason why a gas 478 block couldn't handle lots of boost. Mine will only handle 11 pounds or so and I'm not worried at all. With it, came a Clark VO 285 transmission with a .83 overdrive. My cruise RPM at 60 will a little less than 1900 RPM.

[Jeannie]

This thread has been cleaned to bring it back on track. Remember Gentlemen, we have rules in this forum.

Stay on topic. Cutty, good luck with your project.

[bigblockv6]

The 478 has a longer stroke than the other V6's, hence the reason for external balance in this case.

It's absolutely impossible to internally balance the 478 crank, I requested the balance shop to see what they could do and the end result was they put as much weight as they could to the crank but still needed a good amount of weight on the flywheel and front pulley. The only internally way to fully internally balance one is to stroke it and increase the bore, the end results would be 523 cubic inches.

[turbobill]

The Clark is a five speed. If the nomenclature only had a letter, it's a non overdrive. An O after the letter indicates overdrive. For the other larger truck transmissions, I'm not sure how they denote it in their nomenclature.

I was lucky as this is the transmission that was behind my 478. My truck is also a 4 X 4, but it has a divorced transfer case so it is only a simple matter of fabricating a shaft between the transmission and transfer case.

[1972RedNeck]

Finding a Clark 280 or 285 overdrive is not going to be easy. I have been searching for one the past 6 or 7 years for my Ford to no avail.

My plan is to just use the large truck adapter plate and flywheel and run an overdrive tranny with an SAE bellhousing pattern. The Spicer/Tremec 6+1 seven speed has been turning my crank of late but any Fuller 5 or 6 speed would work fine.

[Cuttyman9]

I figure if I shed serious weight off the 478 rotating assembly by stroking and aftermarket parts that aren't giant I should be able to internally balance it.


Shoot! there sure are a lot of options, I just need something OD to make it streetable and something that bolts up since my engine combo is gettin more exotic haha.

What would you recommend for an OD equipped trans that's relatively readily available for a reasonable price??

[Cuttyman9]

Are there big truck transmissions available that have a married transfer case and OD?
Would they fit in the run of the mill c20's?

[1972RedNeck]

Are there big truck transmissions available that have a married transfer case and OD?
Would they fit in the run of the mill c20's?

No, but custom adapters have been made to couple 6 speed fullers to married transfer cases.

http://www.4btswaps.com/forum/showthread.php?18717-Fuller-6-Speed-w-married-NP241-Transfer-Case

[turbobill]

Are there big truck transmissions available that have a married transfer case and OD?
Would they fit in the run of the mill c20's?

I don't know of any as even the big stuff years ago used divorced transfer cases.

I would find a NP205 divorced style out of a 70's Dodge 4x4 P/U or International light line 4x4. Both had the front drive coming out of the right side if you are using a 60's to late 80's GM front drive axle.

Ford also used the 205 divorced style through about '77 on the F250/350, but it drives on the left, so you'd need a Ford front drive axle.

The 205 is all gear drive and is the strongest of the light truck models. I converted my truck (a 1965 Chevy) after the naturally aspirated 454 chewed up the original Timken T221. It has held up under the turbocharger since 1986.

Are you wanting a manual transmission only or are you also considering an automatic?

[Cuttyman9]

I'd like to stay manual, it's more fun and usually can handle a lot more as far as trucks go.

It's an SM 420 right now.

Now the part I'm concerned about is mounting a divorced Tcase setup as is have to create all the mounting and link the two together somehow I would assume with another driveshaft between em.

[Cuttyman9]

Basically short of an nv4500, np435 or np420 I kinda am a noob to 4x4 transmissions.

[turbobill]

All the newer stuff has married transfer cases. Most manufacturers started marrying transmissions and transfer cases in the later 60's. I mentioned some exceptions in an earlier post.

GM went to left side (front axle) drive starting with the GM T400 trucks in '88. If you use a transmission/transfer case from one of those trucks, you'll have to use a Ford front driving axle if you are going to go with a straight axle. Somewhere a long the line, Dodge went to left side drive too (maybe '94?). My 97 Dodge has a Dana 60 front axle with left side drive.

Some GMC 305's had Chevrolet automatic transmissions behind them in the mid 60's, so sourcing the necessary parts would allow you to use a 700R4 or 4L80E Overdrive automatic behind your engine. The older 700R4's don't use a computer to control them (pre '94), so using one of those would be easy. 4L80E's are electronically controlled, so a stand alone controller is necessary (expensive), or there is a kit to make it a full manual shift.

The 700R4 can be built strong with aftermarket parts. The 4L80E is strong enough as is. Many 4 WD trucks came with these two transmissions, so finding one with a transfer case attached is easy depending on where you live. (they are all over up here in the snow belt)

[Cuttyman9]

Interesting, I'm aiming for a manual.

I'm okay with a divorced or married one although married would be simpler overall.
Initially I hadn't though about doing it that way.

I did find a Dana 60 front from a Ford F-350 from the 70's.
That probably would be better than the 10 bolt I have but I don't know much about closed knuckle front axles.

[turbobill]

Dana 60 is the strongest. I prefer the closed knuckle axles as the axleshaft u-joints run in gear oil and are protected from outside contaminates. The closed knuckles disappeared when disc brakes were installed. (at least with GM)

[Cuttyman9]

Ah gotcha, I may have to consider it then since it's really cheap and at this stage the only real downfall is I'd have to hope Fords frame is the same width haha.

Bigblockv6 I didn't realize you're relatively nearby.
Pretty cool!

[1972RedNeck]

at this stage the only real downfall is I'd have to hope Fords frame is the same width haha.



It is. These old ones are all 34" frame rails.

[Cuttyman9]

Interesting, guy claims it's a 74 closed knuckle drum

So long as it's able to be converted to disc I don't care if it's from something else.
I may run a divorced T case so if that's the case I should be able to find a driver side drop.

http://i1307.photobucket.com/albums/s589/cuttyman9/C47617F1-A3E3-4CAB-99C0-33B08330A460_zpsi1pgvtmi.jpg (http://s1307.photobucket.com/user/cuttyman9/media/C47617F1-A3E3-4CAB-99C0-33B08330A460_zpsi1pgvtmi.jpg.html)

This would prolly suit the build far better cuz I was thinking if this turns out to be a blown 478 even it's going to put enough torque to hurt just about any front axle.

[Cuttyman9]

Blower and the adapter are here!!

http://i1307.photobucket.com/albums/s589/cuttyman9/franken20/2E31F50E-4C87-41A5-A01C-98832CA6DAD6_zpsjrih1ikw.jpg (http://s1307.photobucket.com/user/cuttyman9/media/franken20/2E31F50E-4C87-41A5-A01C-98832CA6DAD6_zpsjrih1ikw.jpg.html)

http://i1307.photobucket.com/albums/s589/cuttyman9/franken20/E66B83FC-4D90-4A62-837C-BE7337B0EA51_zpsxoi0emql.jpg (http://s1307.photobucket.com/user/cuttyman9/media/franken20/E66B83FC-4D90-4A62-837C-BE7337B0EA51_zpsxoi0emql.jpg.html)

http://i1307.photobucket.com/albums/s589/cuttyman9/franken20/E7966FD3-081F-40FF-A5EB-E9E6C838D2EB_zpslcp0ots3.jpg (http://s1307.photobucket.com/user/cuttyman9/media/franken20/E7966FD3-081F-40FF-A5EB-E9E6C838D2EB_zpslcp0ots3.jpg.html)

[ManicMechanic]

If your going the divorced route and pass drop you have a few option. The New process 200 from the 50s dodge power wagon is a good case and not to hard to come by. Also GM used a New process 205 that is good. They are both gear to gear cases with a 1.96 low range. If you want to go divorced and drivers drop your only real option is a ford New Process 205 but they are hard to find and harder to find hard parts for.

[bigblockv6]

If your going the divorced route and pass drop you have a few option. The New process 200 from the 50s dodge power wagon is a good case and not to hard to come by. Also GM used a New process 205 that is good. They are both gear to gear cases with a 1.96 low range. If you want to go divorced and drivers drop your only real option is a ford New Process 205 but they are hard to find and harder to find hard parts for.

The problem with the Ford NP 205 is the front drive line output is on the driver's side, the NP 205 to use is from an earlier Dodge truck.

[Cuttyman9]

Well I think I'm changing gears a bit in terms of front axle with the blower and the torque output of the v6 stock in going to need more heavy duty (also because if I can't find 4.10's for the eatons I'll have to run 40's lol)
So I located a place that would build me an eaton front axle.
I need to track down a local dana 61 from a 87-93 dodge 3/4 or 1 ton and an eaton rear axle with 4.10's and another drop out with 4.10's

It might be overkill but at least I can carry a spare drop out and get out of a bad situation and it will handle the big v6 output with the blower.


That thing sure is exciting to stare at lol.
I got the right tubing (turns out the port holes are 1.25x2.5 each and I found tubing to match)
I think since the magnum heads don't have a solid partition between ports I'll sharpen the bit between em and run a single port to the paired cylinders

[Cuttyman9]

Located a 478 too btw
Should be able to build that one when I have the opportunity to go get it

[TJ's GMC]

Located a 478 too btw
Should be able to build that one when I have the opportunity to go get it

Hope you get it! I had the chance to get one for cheap, but passed because it was pretty rusty. Parts are scarce to.

[Cuttyman9]

Yeah, I'm going to use as much off the 305 as possible.

I'll keep y'all posted.


Side note, anyone have the horns and roof running lights off a big gmc truck? Like a 4000 series?

[Cuttyman9]

Looks as though the bell housing pattern on this is the same as the big 6s so I really just need to adapt the 8 bolt flywheel to fit under this or see about a custom one since this bellhousing fits my truck.
I'll just order an RXT clutch from McLeod to insure it handles the torque.

Sadly my crank pulley and timing plate are bent so I need to look into sourcing those.

If I flip the pulley it should work perfect in adding extra clearance for the blower belt as keeping it close to the motor is ideal.

Now if I cut off all the water pump stuff and run an electric pump, would you guys happen to know of a powerful pump?
This would also shave some weight too.

[bigblockv6]

If you're going to use the 305E bellhousing you'll definitely need the right 8 bolt flywheel for the 478. There were early 8 bolt flywheels used on 62-65 6500 series trucks that were the correct diameter and if you got a hold of one of these it would require machining an adapter to accept the smaller light duty pilot bearing because the hole in the center is much larger. The other alternative is a 379 flywheel if you can find one which is a straight bolt in. Myself I went with a custom flywheel from Tilton Engineering and of course it was balanced with the whole rotating assembly of the 478M, a good amount of weight was added to the flywheel. Another issue I need to bring up is Tilton never machined the flywheel surface facing the engine block to clear the four bolts that bolt the bellhousing to the engine block, that machined relief area is very evident on a 305E flywheel. I ended up grinding down the heads of the 4 bolts to achieve the right clearance:ok: Here's a pic of my custom 478 flywheel:upyes:

[Cuttyman9]

Ah, well I may just do the custom route.
So I wanted to consider the NV4500 in this which requires an adapter so I may have to space out the flywheel anyways.

I'll def have some balancing to do because I think I'm gonna just shoot for a custom offset ground crank and different rods/Pistons. Knowing JE will make a custom 5.125" piston makes me more interested in that than to retain the weight of the giant 4 ring cast factory ones and I can jump to 8.5-1 compression ratio.

[bigblockv6]

Don't think you'll need to space out the flywheel, NV-4500 conversions have been done before on these engines. Go to Jolly's 6066GMCguy.org site, there is an NV-4500 conversion in there. Some custom pistons with 3 rings, Chrysler 426 Hemi type rods with a turned down and stroked crankshaft will result in a 500 plus cubic inch screaming V6:upyes:

[Cuttyman9]

Yeah, I considered that from
The other build but there might be more available in a sbc rod journal (2.0") to pick up 1.6" stroke over the 478 stroke for I think roughly a 678

[Cuttyman9]

Having trouble finding the conversion parts for sale. In the trans section it just lists what they came with from the factory.

[TJ's GMC]

Some custom pistons with 3 rings, Chrysler 426 Hemi type rods with a turned down and stroked crankshaft will result in a 500 plus cubic inch screaming V6:upyes:

THAT and a supercharger! :teehee:

[Cuttyman9]

Any links to the specific conversion parts page?

I only had luck finding people asking about it

[Cuttyman9]

Going slow.
Been tinkering on a few other projects (trans am is pitching a fit, celica is getting closer to being v6 powered and the Z is closer to drivable lol)


Did source the tubing. The blower is awesome to stare at!

[TJ's GMC]

Little progress is better than no progress. :thumbsup:

[Cuttyman9]

Definitely!

The truck hasn't seen much but the celica trans am and Z have seen a ton and the weird swap for the chevelle is gathering parts fast(although you guys will not like that idea, especially what's his face that was blasting me for building a v6 over a Chevy 8 lol, might make him cry!)

The celica is so close to having a 3.5L V6 and the 300zx is close to one piece and almost road legal.
The firebird is eating starter gears and flywheels but at least i have it almost in one piece and close to running well.

Another thing I came up with, so given I had the 3D printer I'm thinking it might be advantageous to print myself a piston, rod and crank throw to test fit to see if I can really offset grind to 5.18" stroke.
I think that shouldn't be a difficult task I can glue in whatever Isn't printable to match the crankshaft.

[Cuttyman9]

478's are mine, my plan is currently to try to swap one 478 in to replace the 350 Chevy, I need a 379/432 flywheel if anyone has the small one.

That's the main hurdle, I'm going to rock the stock manifolds since I don't want to build two sets of headers (one set for magnum heads and another when the blower stuff comes together for the standard ones)

Magnum heads don't work for me so I'll have sets for sale.

Progressively getting there!

[bigblockv6]

You will need a 379 Flywheel for a bolt on installation or an early 62-63 478 flywheel that can be modified. The 432 Flywheel is much larger in diameter and won't fit in the light duty truck bell housing. The other alternative is a custom Flywheel which is the route I chose but it must be balanced with the whole reciprocating assembly, a pic of the custom flywheel is included here:upyes:

[Firepower]

A couple points on the crank plan:
2" SBC journal is pretty small, for strength and for lack of journal overlap. Add a blower and cracks are almost a certainty.
Reducing journal size by offset grinding only adds the amount of stroke that journal is reduced by, not double. 2.2 BBC gives up to .600 more stroke, .300 throw. Welding would allow more, obviously, and/or bigger journals.
7.2" rods stock, easy enough to source longer BBC/BBM spec ones.

Sonic checking any old iron block is a good idea. It's not improbable that it would go .125 over with meat to spare. 5.25 Continental aircraft pistons are light.

[Cuttyman9]

If you move it out 0.811 on one throw (2.811 to 2.0) double it and it gives you the stroke increase since that would be the bottom and the top of the cylinder.

We shall see what the machinist recommends. If he says it's doable I'll give it a shot.

It won't see much more than 8psi.
No need to spin a big roots that hard.

I've got a headgasket lined up. Cometic will do copper ones if I send in my old one.

Je said they can do pistons around that size.

Rods will be interesting as is prefer to buy em off the shelf.

[Firepower]

By reducing it .800, you move the center by .400, that you double for stroke.

Not much for budget over 7.200, so unless the custom pistons are also super tall deck height, it'll get pricey.
http://www.ebay.com/itm/Crower-7-500-Big-Block-Chevy-Rods-Gun-Drilled-Brand-New-/200736254535

I get custom Cometic gaskets often, and also plan on for the 478+

[Cuttyman9]

Yes, my mistake.

Either way, I'm not concerned about the crank.

I would be buying eagle rods or something like that.
Highest quality stuff is not important as this won't see over 4500 rpm.

[1972RedNeck]

Yes, my mistake.

Either way, I'm not concerned about the crank.

I would be buying eagle rods or something like that.
Highest quality stuff is not important as this won't see over 4500 rpm.

When you go to order head gaskets, let me know as I would like to buy a set as well. It might be cheaper if we order a couple sets...

[Cuttyman9]

Will do.

[yeshua63043]

Did you ever get your V6 emblems? I've got a pair I might be willing to part with.

http://6066gmcclub.com/picture.php?albumid=344&pictureid=4313
http://6066gmcclub.com/picture.php?albumid=344&pictureid=4314

[Cuttyman9]

I did, thank you!

Still tracking down some horn stuff from an old C50 or something and the roof lights(if they are metal housings)

[bigblockv6]

I did, thank you!

Still tracking down some horn stuff from an old C50 or something and the roof lights(if they are metal housings)

As in roof lights I have a quite few used ones if you're in need of any:upyes:

[Cuttyman9]

Do you have any pictures of them?

I'd like to put 5 on the roof and mounts some horns like the big trucks have maybe hook those up to an air compressor (as if the blown v6 truck on 40'a isn't enough to get people out of the way haha)

[bigblockv6]

They're the same ones that are on my 68, I bought a whole bunch of them about 11 years ago. They just don't have the rubber base boots like my 68 does which were factory installed. I'll dig them up this weekend and see what I got, I also have the factory GM diagram with the correct mounting instructions which include measurements.

[Cuttyman9]

Pm me some pics, I can probably make my own plastic isolators or something.

[Cuttyman9]

Got the big thing apart!

Can't get the stupid time cover off cuz the balancer is on there!

Had to buy bolts and washers, the one doesn't turn over. Dumped some atf on the pistons, one is good, the other two aren't. Gonna try the other bank soon.

[bigblockv6]

Try some Marvel Mystery oil or penetrating oil, let it soak real good. I had a 478 that got exposed to the elements and finally freed it up but one piston ended up getting destroyed because there was just too much rust in the cylinder wall.:pullinghairout:

[Cuttyman9]

Got one loose, I think the other is loosening. The other 4 aren't budging so I'll probably bang em out once the crank is free.

[Gwhizzard]

i know this is old but any update on this thread????

[Cuttyman9]

A good deal of progress was made.
And then sorta undone.

I picked up 2 478’s. One rebuild and one crusty.
Stripped the crusty one and sold the rebuilt one.

A barn fire happened, killed a few engines and I’m uncertain if the crank or block is still usable…
I still have the initial 305. Since then I’ve developed a turbo kit for it I developed a lot of other parts through 3d printing but a few have stalled due to not having a good place to send parts to be cast. (4bbl intake manifold, water pump less front cover, valley cover, etc…)
I was under the impression someone could make a custom flywheel that would then be available off the shelf.
Sadly as soon as I spent the cash for the bellhousing adapter for the S6-750 from a 6.0 ford diesel they went MIA and without a flywheel I’m dead in the water on that project.
The supercharged option is still on the table but the turbo stuff was far cheaper and it is definitely an exciting one.

I’m at least closer to a driving 4x4 truck with a K20 chassis now ready to go under my C20 body but it’s got a 454 in it and I’ll probably keep that for a little while because I really need a 4x4.

None of this project has gone as planned in terms of procuring it all. it seems between bad natural events and people who don’t follow through I’ve been having a **** of a time.

Between that and all the other vehicle projects I’ve been “distracted” (I’m up to 16 vehicles total)

[Prowbar]

Too bad about the fire, been through one myself too. It sucks, everything is destroyed, and nothing you can do about it.

[Gwhizzard]

A good deal of progress was made.
And then sorta undone.

I picked up 2 478’s. One rebuild and one crusty.
Stripped the crusty one and sold the rebuilt one.

A barn fire happened, killed a few engines and I’m uncertain if the crank or block is still usable…
I still have the initial 305. Since then I’ve developed a turbo kit for it I developed a lot of other parts through 3d printing but a few have stalled due to not having a good place to send parts to be cast. (4bbl intake manifold, water pump less front cover, valley cover, etc…)
I was under the impression someone could make a custom flywheel that would then be available off the shelf.
Sadly as soon as I spent the cash for the bellhousing adapter for the S6-750 from a 6.0 ford diesel they went MIA and without a flywheel I’m dead in the water on that project.
The supercharged option is still on the table but the turbo stuff was far cheaper and it is definitely an exciting one.

I’m at least closer to a driving 4x4 truck with a K20 chassis now ready to go under my C20 body but it’s got a 454 in it and I’ll probably keep that for a little while because I really need a 4x4.

None of this project has gone as planned in terms of procuring it all. it seems between bad natural events and people who don’t follow through I’ve been having a **** of a time.

Between that and all the other vehicle projects I’ve been “distracted” (I’m up to 16 vehicles total)


Sorry to hear about the fire! and any of those designs can you post up for others to see? I don't wanna steal thunder but we might all be able to help and reap the rewards from it. I'm actually looking into doing this as well and build something similar just waiting until after i finish up other projects

[Cuttyman9]

I’ve posted a lot of the progress under the tag #franknc20 on IG.

https://www.instagram.com/p/CHEoWkInufn/?utm_medium=copy_link

https://www.instagram.com/p/CGs84vtnJ06/?utm_medium=copy_link
^if people need these I have more.

https://www.instagram.com/p/CIUOlI8nlkG/?utm_medium=copy_link

https://www.instagram.com/p/CJ9Su3cHLhv/?utm_medium=copy_link
Timing pointer has been added.

The truck has seen some progress at least.
350 Chevy was removed, picked up a K chassis for switching the cab onto (454 equipped right now) cleaned up the interior
https://www.instagram.com/p/CSz2VhyvwvT/?utm_medium=copy_link

https://www.instagram.com/p/CJwqtVEHWJ3/?utm_medium=copy_link
https://www.instagram.com/p/CJwqlNJnvKH/?utm_medium=copy_link
A couple shots of the 4 barrel intake.
Can’t find anyone to cast the **** thing so it’s on the back burner.

No pics of the current bellhousing adapter, it’s 1/2” thick plate this time instead of what I designed with aluminum (2.25” thick)
Sadly the guy who I was talking with about making an off the shelf flywheel bailed basically. He’s been super unresponsive.
https://www.instagram.com/p/CD9roP1n5P6/?utm_medium=copy_link
This is the transmission it’s designed for. Ford 6.0 s6-750
They are pretty inexpensive and this setup would make it bolt up

[Cuttyman9]

I lied, I found a picture

https://www.instagram.com/p/Ca2i-XTPt9X/?utm_medium=copy_link

[FetchMeAPepsi]

Can you just paste the pictures here so we can see?

[Cuttyman9]

I’m not seeing an option to upload for the few I have with me, the majority of these are somewhere on my external hard drive now.

[FetchMeAPepsi]

I’m not seeing an option to upload for the few I have with me, the majority of these are somewhere on my external hard drive now.

Just click the paperclip after you click "reply"

[Gwhizzard]

i wont lie.. i don't have a Instagram account and for some reason my computer wont let me even attempt to open those links. But instead of casting the intake what about machining it? or using tube? I am just guessing but i haven't seen the pictures of it yet

[Cuttyman9]

Just click the paperclip after you click "reply"

Everything asked for a URL.


Sorry, Instagram opens the links on my phone, I’m not sure why they don’t work on your computer.

The idea wasn’t to make a one off. The idea was to have an off the shelf manifold for these engines.
Cnc was 1500 an intake easily if not more.
Tube will work about as poorly as the stock intake.

Casting is the way to go.
I might have found someone so fingers crossed.

[FetchMeAPepsi]

Everything asked for a URL.


Sorry, Instagram opens the links on my phone, I’m not sure why they don’t work on your computer.

The idea wasn’t to make a one off. The idea was to have an off the shelf manifold for these engines.
Cnc was 1500 an intake easily if not more.
Tube will work about as poorly as the stock intake.

Casting is the way to go.
I might have found someone so fingers crossed.

The paperclip next to the smiley face is the one you want. It opens a new window with "Browse" buttons.

[Gwhizzard]

Gov computer lol!!!! i gotcha i see what your saying with the tube. i just didn't know exactly what it looked like. But i hope so that would be nice to see

[Cuttyman9]

Sorry, I was using the quick response.
I’ll post the ones I have with me if it lets me.

[Cuttyman9]

The one is the older one i printed the snapshot of the model is the more recent one.

I’m hoping I can influence the design a bit if the company I reached out to develops their own.
A few people requested quadrajet flange pattern, I added that and enough meat that people should be able to cut material from it to make it work. It also has hardware locations for those too.

No exhaust crossover, it’s a bit taller than stock but that’s to get a smooth path to the port entrance.

[Gwhizzard]

The one is the older one i printed the snapshot of the model is the more recent one.

I’m hoping I can influence the design a bit if the company I reached out to develops their own.
A few people requested quadrajet flange pattern, I added that and enough meat that people should be able to cut material from it to make it work. It also has hardware locations for those too.

No exhaust crossover, it’s a bit taller than stock but that’s to get a smooth path to the port entrance.


Nice..:thumbsup: Ill talk to a buddy of mine that is in the custom world and see what he might be able to help with. That's nice Though big thumbs up!!!

What printer are you using to print the components???

Is that a Holley bore setup as well?

Also i wonder if we could add injector ports for fuel injectors to sit??? just an idea.

Ive been looking alot into trying to configure a Sequential fuel injection setup for these with Coil on plug setup. In research phase right now though lol

[Cuttyman9]

That would be legit, I wouldn’t mind trying to make it still if the other company does since I dumped so much work into it.

Holley flange so the standard one, I only added a quadrajet cuz a couple people liked those more and it wasn’t much more effort.

I printed it in PLa on my Hictop D3 hero

I figured fuel injection wise they’d need arms for the rail and what not too so I would just leave it plain. Most who go fuel injection these days run the fitech style carb one.

[Gwhizzard]

That would be legit, I wouldn’t mind trying to make it still if the other company does since I dumped so much work into it.

Holley flange so the standard one, I only added a quadrajet cuz a couple people liked those more and it wasn’t much more effort.

I printed it in PLa on my Hictop D3 hero

I figured fuel injection wise they’d need arms for the rail and what not too so I would just leave it plain. Most who go fuel injection these days run the fitech style carb one.



Understand that.. Awesome i was just wondering bc it is standard size for most throttle bodies with TPS sensors out there... With the fuel injection i looked at the FI Tech and Holley setup but wanted something different like ma MS2 or MS3 setup and be able to program it more myself that's why i didn't know if there is a way in a different design with injector bongs that are closed up and just require drilled. But it is very nice. I appreciate the pictures it helps me visualize kind of what i wanna do with mine. If they do make it and give a good price we could have a poll and see how many would go in on it as well and get their own. Maybe cheaper that way as well

Nice printer setup. Im looking at ender 3 pro to get started. Figured it would be a good base line and move up as needed to bigger printer for parts.

[Cuttyman9]

Yeah, there was more DIY FI stuff being voiced on the group than stuff they planned to do with this intake so I left that stuff out.

There also is no guarantee that They will be using my design at all so it may not matter.

Ah yeah, I’ve always wanted the biggest print area possible because you can’t add more as easily as you can make small parts on a big one.
I’m looking at resin printers next

[Gwhizzard]

Ah i gotcha. I seen some people talking about the FI setups from GM or holley and FItech but understand that. i Hope they take it on for sure.

[Cuttyman9]

They posted publicly so I figured I’d share.

Show some support for this so they know they aren’t developing stuff for no reason!

I’m certain if carb intakes sell then valve covers valley covers, maybe even front covers in aluminum will be possible!

[FetchMeAPepsi]

How about a link? Searching for aussiespeedperformance brought me nowhere.

[Cuttyman9]

https://instagram.com/aussiespeedperformance?utm_medium=copy_link

[James]

I had also found this link:
https://www.aussiespeedshop.com/

[Gwhizzard]

Shoot yea i wish someone stateside would take it on as well!!!!

[MoscowMule]

Hey you all.I now have three 305's can't find a block worthy of just honing and throwing new rings in.Since I can't find over sized pistons and rings.I have wondered if the 305 could be bored to accept the 351 pistons.My machine shop guy isn't sure and he wants $225.a hole to sleeve.I'm going to look at a 351 in the morning.Hoping the block is good and throw rings in and go.If not I could get pistons reasonable if you all know if the 305 block could go that far.
Thanks for any advice.Moscow Mule

[Cuttyman9]

If you’re in for some fun- bbc pistons and Jaguar 4.2 i6 rods.
Have them offset grind your crank to fit the jag stuff and fit that to your deck height.

I have rods it should be doable with some off the shelf flat top bbc pistons