The Stovebolt Site Forums The Parking Lot Big Bolts 51' GMC 640 - 671 Detroit ??

I've found in a vacant shipyard a 1951 GMC 640, It has a gas engine I can't identify, alot of mods over the years, including a dump bed. It seems to be a ex-Navy rig. My question is, on the plate in the glove box it says "engine 426" I'm assuming it was a 671 Detroit. Yes? The cab is perfect no dents or rust,only missing the right lower engine cover.The tires are newer and not weather checked. No one knows who owns it.I've got the address of the last registered owner from the glove box and search is on.

I don't think a 6-71 GMC is a gas engine...pretty sure you meant diesel!

Stuart

The diesel engine in a 640 series should be a 4-71. GMC offered a 426ci gas engine in this model.

What the heck does this 426 gas motor look like? I knew the engine in the truck was not the 671 diesel, I was wondering if the original engine was a 671. I just multiplied 6x71 cu.in.and came up with 426. This engine in the GMC is a big v-8 and I know my Chevy's and this is not any Big block late model unit. I'll dig around today and see if I can I.D. it..........Rick :confused:

The 426 gas engine was an inline six with a zenith carburetor, so I guess it no longer has the original engine.

I just checked the truck out and i cannot I.D. this engine. It has 8 bolts on valve covers, real wide across the intake manifold, front distributer, the runners on the intake manifold dont go to the forward cylinders, they start at the second ones. I cannot find any company markings on it. The water pump is a huge unit that looks like a turbo casting, strange. Someone out there knows what this is.......Rick

suggest you take pictures and post a link. use something like webshots,photobucket or a similar site. A 620 down the road has a 471 the 750cannonball has a 671

pictures clutch

this sounds VERY much like a continental engine. if it is, good luck with parts.

Yes I would very much like to see some pictures of it. Koolkar may have some thing there. Continentals where a widely used industrial engine in the day. You may also check with the guys at A.T.H.S.

That plate on the glove box lid, you speak of, is the "GMC Truck Parts Identification" Plate. This plate was installed on all GMC 450 series, & larger trucks. This plate informed you of the type engine, trans., rear axle, springs, brake type, wheel type, etc. of these trucks, as they rolled off the assembly line. So according to this plate, this truck in particular, came off the line, with a 426 GMC 6 cyl. gas engine.

The truck did come with the big six as you guys said. I'm in process to pick up a digital camera and join this century as far as pictures goes (i.e. I'm broke right now)My initial gut feel was that it is a Continental as Koolkar has said.It has a 600 CFM vacuum secondary 4 barrel on it. any one know any distigushing marks of a Continental V-8 ?............Rick

with a regular film type camera even the disposibles when you get the pictures developed you can have them put on cd as well then load them on your computer. cost about 10 bucks at walmart. not as convienet as didgital but cheaper shortterm.

So what engine does it have, I guess you figured it out since its in your sig and this is an old topic. Any pics?

Hy peytonmaterne, I'm sure he doesn't want to talk about it, it turned out to be a big F@#d V8, he drove it home from the boatyard, and has been looking for a GM engine of some type for it ever since.

Yikes, that sure is a weird combo, must have been whatever they had laying around. I'm surprised it cleared the steering box.

If it is a big Ford V8 the way he described the intake starting at the second cylinder back my guess would be that the ports are stacked on top of one another and it is a 292 Y block. If this is true should be some good trading stock, certainly not a bad thing.

I wonder if they reused the original trans. Can a Y-block be mated to an sae flywheel housing?

Hey Guys it's been awhile, It's a 534 c.i. Ferd Super Duty with a Spicer 5 speed w/ PTO. No clearance problems at all, just tissue rejection and the smell is terrible. I'm surprised 3B stood up for me.I'll be hauling about 30 family members this Christmas around the niehborhood in the back singing Christmas carols. Later,Rick.