The Stovebolt Site Forums The Shop Area Engine Shop GMC 478 engine? Come in!

Good morning all!
Yesterday I was venturing at the local scrap yard and notice an old GMC fire truck getting scraped. Talk to the owner and manage to get the engine and tranny for, wait for it... 150.00$. a nice GMC 478" with only 22,000 miles.

Now, my head is full of nonsense ideas for it. I was thinking about dropping it in my 53 two ton Chev. Any idea if it would fit without butchering too much. I have hard time cutting something all original, but the 235" is kind of shy in power for today's driving. I often pull a 14,000# trailer going to antique tractor pull / show / plowing match. I'm not looking to go at an high rate of speed, just a bit of get up and go leaving the stop sign.

Any how, I'm going to get the motor this afternoon, and take more mesurment. Even if the engine sit in the corner of the shop for a while, I can't let it go for scrap.

If you guys have done a similar engine transplant, advise would be great.

Thanks,

J. F.

You'll have to do some serious upgrades on the front springs- - - - -that thing is HEAVY! You'll also need to add a fuel tank or three- - - - -the truck will automatically turn in at every gas station you pass! On the upside, you'll have some massive torque and pulling power. If the transmission happens to be a Clark 5 speed with overdrive in 5th. gear, you sort of got a free engine out of the deal!
Jerry

I had one in a 1970 Chevrolet T80 COE. It had about 250 HP at 3700 rpm and 440 lb-ft torque at 1400 rpm...it's a gas motor that runs like a diesel. The engine alone will weigh more than 900 pounds

Like Jerry said, will pass anything but a gas station. My truck had a 5+2 trans/rear set up with no OD, so max speed was about 55 mph.

Mike B

Got the engine out of the donor frame today. Yeah! It is BIG! Sitting next to a 350 Chev...., Even the 427" look small...
It came with a Clark 5 speed direct. After a few mesurment and a couple beers I'm coming to the conclusion that the engine is a bit big for this truck. I think I'll go with my first choice, the 350" with the 5 over.
Well, the 478" is for sure a cool engine, the price was right. Now, will just have to find a project for it.... Suggestions???

I drove some GMC trucks with the 478. Way to heavy for anything under a 2 ton. Most were in a 5 or 10 ton. If you put in something, don't run it WOT for any length of time. One truck we had was geared to a max speed of 62 mph, and used for highway travel. At about 100,000 miles I put a rod through the block on the 3rd engine. Truck was sold to a farmer. For info, go to Jolly's site www.6066gmcguy.com/EngineData.html. For mileage, it wasn't bad. Don't think I ever emptied both tanks (100 gal.) in a day, many days were 500-600 miles. Not bad for hauling 15 tons of lumber.