1962 GMC 478M V6 Swap

[padresag]

the major difference in weight would be the water pump and mounting casting. they do not inc flywheel, compressor, alternator or p/s pump. a complete basic engine only
changing the water pump and mounting reduces weight and makes for more room, but there are other changes to do such as timing chains and gears and a few other things
ron

[C10 - C90 Bill]

Originally Posted by padresag

In 1962 the 478 V6 was introduced for use in the 6500 series trucks.

That is exactly right. They was some doubt about that for a while, but it seems to be cleared up now. I knew it from driving one. I drove a '62 GMC 6500 with a 478. The engine was a real power house. I can just imagine what a Magnum will be like.

Bill

[C10 - C90 Bill]

Originally Posted by padresag

In 1962 the 478 V6 was introduced for use in the 6500 series trucks.

That is exactly right. They was some doubt about that for a while, but it seems to be cleared up now. I knew it from driving one. I drove a '62 GMC 6500 with a 478. The engine was a real power house. I can just imagine what a Magnum will be like.

Bill

[Fred T]

I drove some 10 tons with the 478M. Good engines, but they will not last at high rpm. One we had averaged 25,000 miles per engine, with an operating governor. Around 100,000 miles I picked up a piece of the block bigger than my XL hand. The boss put in another engine and sold the truck. The engine suffered from a huge crankshaft and poor balance.

If you go through with the 478, balance the rotating assembly. I would also recommend gears of around 3.08, the engine is a torque monster. If you can find (or afford) one, a Clark 5 speed OD works good behind the engine. But you will have to make room for the original bell housing.

[Rezzato]

Sorry for the long delay, I have been busy with school but it is spring break now.
Took the engine apart yesterday, here are some photos.

Heavy duty bellhousing removed:

Dual clutches:

Notice the smaller 379 flywheel which fits in the light duty truck bell housing over the 478 flywheel:

Light duty bellhousing on 478:

Look at the size of the pistons:



I'll be getting the flywheel and bellhousings back from the machine shop in a day or so.

[duallyjams]

I see it has the tach drive off the cam also.

[Rezzato]

Finally got most of the engine together. I was able to find an engine gasket set from ebay for $49.99. That was a steal compared to the $230 everyone else was asking. The company I bought it from must have randomly found it in their inventory because they don't normally stock it and tags on the gasket package said Chevrolet 478M. Next week I plan to start the engine outside of the truck and time permitting hopefully get it in.


I did not leave it on the oil pump for very long.

[1972RedNeck]

Originally Posted by Rezzato

Finally got most of the engine together. I was able to find an engine gasket set from ebay for $49.99. That was a steal compared to the $230 everyone else was asking. The company I bought it from must have randomly found it in their inventory because they don't normally stock it and tags on the gasket package said Chevrolet 478M. Next week I plan to start the engine outside of the truck and time permitting hopefully get it in.


I did not leave it on the oil pump for very long.

Any updates?
Posted via Mobile Device

[Backpayne]

Last time he was on the forum was 5/23/2012.

[MusicMan70]

I recall from the 6066 GMC Forum that he sold this engine before it got installed.

[TJ's Chevy]

That's a darn shame. Would have been a neat project.

[factorystock]

The 478's large bellhousing and flywheel issues usually kill the deal for any light duty pickup installation. A more practical power upgrade for V6 people would be to find a complete good running low mileage 351 out of a '66 thru '68 GMC pickup.

[TJ's Chevy]

Originally Posted by factorystock

The 478's large bellhousing and flywheel issues usually kill the deal for any light duty pickup installation. A more practical power upgrade for V6 people would be to find a complete good running low mileage 351 out of a '66 thru '68 GMC pickup.

The smaller 305-351-379 v6 bell housing bolts right onto the 478. The hardest part of the whole installation is locating the small 379 flywheel. But the OP already had that.

[1972RedNeck]

Originally Posted by TJ's Chevy

The hardest part of the whole installation is locating the small 379 flywheel. But the OP already had that.

Yup, I would darn near kill for a 379 flywheel right now.

[TJ's Chevy]

Originally Posted by 1972RedNeck

Yup, I would darn near kill for a 379 flywheel right now.

I'd darn near kill for a Decent priced 478! haha

[C10 - C90 Bill]

There should be a 478 in this truck if it still has the original engine in it, as I believe it is a 6500 series.

Some good truck parts there to boot.

Can't beat the price on it.

Check it out:

https://sfbay.craigslist.org/scz/zip/5904665195.html

[TJ's Chevy]

Originally Posted by C10 - C90 Bill

There should be a 478 in this truck if it still has the original engine in it, as I believe it is a 6500 series.

Some good truck parts there to boot.

Can't beat the price on it.

Check it out:

https://sfbay.craigslist.org/scz/zip/5904665195.html

Dang! Course it would have to be in the next state though. lol

[Rezzato]

I had all of the parts and was ready to move forward but at the time I was slammed with many other things. The engine sat and then was sold to someone. I was told it had some rust in the cylinders but should have easily been salvageable.

Funny, I live in Santa Cruz now and can totally go look at that truck, unfortunately the ad says expired.

[1972RedNeck]

Originally Posted by Rezzato

I had all of the parts and was ready to move forward but at the time I was slammed with many other things. The engine sat and then was sold to someone. I was told it had some rust in the cylinders but should have easily been salvageable.

Funny, I live in Santa Cruz now and can totally go look at that truck, unfortunately the ad says expired.

Any chance you'd have the 379 flywheel still?