Project Blown 305

[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]

Originally Posted by 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.

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]

Originally Posted by 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.

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.

[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!

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