Found a BBGMC v6 401 in TN
 

Guys, I was trying to get this deal in TN to go in my 1957 Western Flyer 4x4 Bus/RV to replace the dead 351 that it came with from the factory. However, after many considerations i thought the 401 was going to be an overkill. Here is the link in case someone is interested: https://www.facebook.com/marketplace...0455533730260/

Instead, I bought a 1969 C30 in TN with a 305. It will be bored to 351 and i will be using the pistons, heads and carb from my 351. My 351 throw not one, not two but THREE RODS and I hope the pistons are still good. This way my bus will continue having a 351 motor as it came for the factory with it's 6 speed allison transmission.

Re: Found a BBGMC v6 401 in TN
 

The GMC V6 engines were introduced in 1960 so that would be impossible the 1957 Western Flyer came with one from the factory. As far as boring a 305 block to accept the 351 pistons that also seem unlikely, it would by far exceed a maximum overbore of .060. The 351 pistons are considerably larger over the 305 piston bore. 4 1/4 vs 4.56.

Re: Found a BBGMC v6 401 in TN
 

You'd be much better off with that 401 than a 305 in something as heavy as a bus. It would definitely not be "overkill" as you say. That 401 probably has way fewer miles than that 305.

Re: Found a BBGMC v6 401 in TN
 

I barely know my butt from my elbow but I can definitely say that boring your 305 to 351 is a gamble. A shop might not even do it for you due to safety.

But...if you grab that 401....you'll be sent to the hospital to have that grin removed from your face. It's not overkill at all, these engines are made to lope along forever at low RPM. You'd just be making it happy and in return it'll make you happy too. Go for it! :upyes:

edit: :welcome: to the forum!

Re: Found a BBGMC v6 401 in TN
 

LOL., that is a funny saying. I am new to all this GMC V-6 Big Blocks but according to Wiki, the only difference between a 305 and a 351 is the bigger bore, improved heads and larger carb. Block is the same as is everything else.

I will try to post some pics of the engine bay but everything is really tight fit in there so I am sure I am sure if came from the factory (in 1957) that way with that engine. I don't know if Western Flyer had access to those engines before GMC released them in their lined but if it was a later down the road add, whoever did that conversion did an outstanding job.

Re: Found a BBGMC v6 401 in TN
 

I'm sure BBv6 will be in to correct us, but I think they had different water jackets (is that a thing?) too to account for the added heat/pressure. IIRC, and I may not, they weren't just 305s with bigger pistons + heads.

Re: Found a BBGMC v6 401 in TN
 

Upload of a 89kb picture failed. Let me try again.

Re: Found a BBGMC v6 401 in TN
 

Pics... fingers crossed.

Re: Found a BBGMC v6 401 in TN
 

The engine serial number in your last photo bears no resemblance to a V6 serial number. The very earliest V6s were installed in a few model year 1959 trucks for testing purposes.

You can find your engine's serial number stamped into the top of the block between the cylinder head and that big alternator of yours. You can see what to look for here: http://www.6066gmcguy.com/EngineData.html

Re: Found a BBGMC v6 401 in TN
 

Looking at the pics of the engine it appears that you have a 351 Magnum V6 which was first introduced in 1966, I would say it's either a 66 or 67 year engine. If you replace it with a 401M hang on to the Magnum heads and manifolds both exhaust and intake.

Re: Found a BBGMC v6 401 in TN
 

Actually I won't correct you on that because what you stated here is true!:thumbsup

Re: Found a BBGMC v6 401 in TN
 

Wow, and it's a 4X4. Anyway, Western Flyer was the forerunner to today's New Flyer, a major manufacturer of transit coaches based in Canada (Winnipeg, I think). Western Flyer used a lot of International gasoline engines in the 50's, chances are this coach had an IH 'Red Diamond' 450 in-line 6. Considering GMC put a lot of effort into marketing the V-6 as a replacement engine for other makes of trucks and buses, this bus was probably re-powered some time in the late 60's by a GMC dealer. Figuring that a 4X4 bus was probably very rare and very expensive, it's not a surprise someone made an effort to keep it going. I have seen many similar vintage Flxible Clipper's with GMC V-6's in them.

Re: Found a BBGMC v6 401 in TN
 

Fellas, although personally I don't recommend it, my late father said he had seen a 305 block bored to 351 but it also had been cross bolt drilled on the main caps like a toro-flow to stiffen the block. I totally agree to replace the dead 351 with a 401.

Re: Found a BBGMC v6 401 in TN
 

IH made a couple smaller displacement Red Diamond engines, according to Wikipedia, they made 318, 361, 372, 401, 450, & 501. Production started in 1941 and ended in 1974. Only some of the engines were available at any one time. Probably the 450 was made the longest, most popular engine of the line, was able to replace sleeves during a major rebuild with block still in the frame. 501 was parent bore engine, no sleeves. Lots and lots of fleets had R-190's and CO-190's with RD-450's for power.

Anyhow, For sure use the 401 V6 to replace the tired 351. Overall size of the big block V-6's very similar, 401 should fit anywhere a 351 or 305 has been. There's pictures and video here of a 478 in a 3/4 ton pickup. Just imagine what a great tow rig that is!

Re: Found a BBGMC v6 401 in TN
 

Thanks, so someone did a great job when they re-powered the bus because it looks like a factory job :-). I am holding on to the heads, carb and pistons (if they are in good shape).

Re: Found a BBGMC v6 401 in TN
 

Western Flyer made have made a retrofit kit. Our Flxible was converted to a 401 with a factory mount set.

Re: Found a BBGMC v6 401 in TN
 

I found something cool about my bus. Seems like it might have been repowered the same time the allison "6 speed" tranny was put in bacl in 1972.

Re: Found a BBGMC v6 401 in TN
 

I am still not sure which to go, either with a Cummins 24V and Allison, a DT466 or DT360 with an Allison y a Hummer 6.5L Optimizer V8 Turbo engine with a 4L80E behind it. The ladder does 250hp stock nand comes with a TC that will need to be switched 180 degree to the passenger side.

Re: Found a BBGMC v6 401 in TN
 

The 401 being a truck engine is a slow engine in the heavier vehicles. Long grades on the interstate can be a challenge. The Allison 1000 conversion in our 47 Flxible made climbing a little better esp in that you have the interruption free down shifting and can hold a gear as long as you want electronically. But still has trouble keeping up on grades.

Re: Found a BBGMC v6 401 in TN
 

Engine came off yesterday. OMG them pistons are HUGEEEE at 4-1/2" in diameter. The space between the bore are like I never seen before. I haven't measure them yet but seems to be about 1-1/2". With that space I wholeheartedly believe that the same block was used for the 305s and 351s just by boring them out.The pistons are trashed though. One is cracked really bad and they are gouged on the upper portion of the piston about 1/8" deep. Heads are perfect and beautiful, lol. Not a single blemish and they are really clean. This weekend I am removing one side head of the 305 to do a comparison between the blocks. I need to find replacement pistons (4 rings) and rods. I hope the local Piston Warehouse can get them cheap. But I am not sure if I want the BB V6 in there. It would be the era correct engine for the bus but I kinda want something more updated that can get up to speed and maintain that speed comfortably.

Re: Found a BBGMC v6 401 in TN
 

I just got off the phone with my distributor and the 351 pistons are unavailable. The guy on the phone was very knowledgeable on the subject and said it would take 401 pistons. Those they have new and cost a whooping $450 for 6 and $250 for rings. So the V6 Big Block idea for my bus is out and gone. No reason to go to bigger pistons if they next person will be stuck with an engine that internals are hard or impossible to get.

Re: Found a BBGMC v6 401 in TN
 

Greetings, I own a 1949 Flxible bus that was re-powered in 1966 with a GMC 401 BB It moves my bus very well and while i wish i did not have to double clutch the trans- it is much more responsive and easier to drive than my other Flxible bus that is powered by a Detroit 6V71. The draw back to the 401 in my opinion is the lack of parts. Trust me on this- be CERTAIN you flush you fuel tanks or you will end up with all sorts of problems - such as stuck valves. Try finding a head set for a 401 while you are broke down 300+ miles for home! Thankfully members on this site where able to help us!

Re: Found a BBGMC v6 401 in TN
 

Greetings, I own a 1949 Flxible bus that was re-powered in 1966 with a GMC 401 BB It moves my bus very well and while i wish i did not have to double clutch the trans- it is much more responsive and easier to drive than my other Flxible bus that is powered by a Detroit 6V71. The draw back to the 401 in my opinion is the lack of parts. Trust me on this- be CERTAIN you flush you fuel tanks or you will end up with all sorts of problems - such as stuck valves. Try finding a head set for a 401 while you are broke down 300+ miles for home! Thankfully members on this site where able to help us!

Re: Found a BBGMC v6 401 in TN
 

Howdy, that is good to know on how the 401s perform. I answered you back via IM and let me know if the link does not work.

Also I have a lot of parts of my 351 that will be for sale soon (heads, carb, intake, 1 or 2 pistons and the front pulley system. I was going to bore my 305 and make it a 351 so I can use my 351 heads (better flow) but 4 of my pistons are no good. I don't know what will go back in my bus but may be a 5.9TD or a Detroit Series 50. Do you know if the 351 heads are the same as the 401? According to Wiki, they just put bigger pistons and heads in the 305 to make a 351, and a stroker crank in the 351 to make a 401.

Re: Found a BBGMC v6 401 in TN
 

According to Wiki, they just put bigger pistons and heads in the 305 to make a 351, and a stroker crank in the 351 to make a 401.[/QUOTE]

Wiki is totally wrong!!:lolsmack2::lolsmack2:The 351 was cast with a larger bore, heads were the same as the 305 though some versions had bigger valves and in 66 the Magnum version with bigger ports and valves was introduced. The 401 wasn't stroked it shared the same stroke with the 305 and 351, it was just cast with a larger bore. In 1973 when GMC introduced the 432 they basically took the 401 and stroked it with the 478 crank to come up with 432ci. I would have to say more members on this site can provide far more accurate info on the V6 than the nonsense from Wiki:ahhhh:

Re: Found a BBGMC v6 401 in TN
 

EEEWWWwww. The 5.9 and it's later Big Sister 6.7 are really good engines, Hard to find one with many miles left for reasonable money. Company I used to work for leased a FreightLiner FL70 with a series 50 engine and Allison trans. Thing leaked oil something terrible, vibrated so bad the driver had to crank the door window down and steady the mirror year round to back into the dock. He could Not get out of that clunker fast enough.
After 4 years my new boss asked my opinion on which truck to lease, another FL70 or a Navistor 4400 with DT466E, Allison, Alcoa wheels, air ride suspension, air ride seat, air conditioning, AM/FM/CD player, it rode better, handled loads better, my suggestion of lower numerical rear gears to increase economical cruising speed helped save time, improved mpg, and driver liked the truck so much he took all his breaks in the truck listening to his CD's enjoying the heater or AC. The Navistor ran over 190,000 miles in 4 years and looked almost like new, chrome and aluminum needed a little polishing. The FreightShaker only got 170,000 in 4 years, and looked about 10-12 years old. The leaking oil blowing all over the chassis did NOT preserve it. Was funny, the Only time the FL70 was loaded even close to it's rated gcwr the leaves in the left rear spring broke, dropped the box on top of the drive tires and ground it to a quick stop, driver was just barely able to get the truck off the road enough to let traffic by, had to tow it backwards to the repair shop, transfer the hot freight to a different truck and deliver it. The Navistor only ever needed normal scheduled maintenance.
I doubt a DT466 will fit where your 351, 401, or 6V-71 could fit, but a 7.3L V-8 might, either Ford PowerStroke or Navistar T444E, very reliable 210 hp.