350 or 400 Pontiac engine in '64 4X4?

[crazyjeenyus]

Originally Posted by D'Monsta

I know this is an old thread and I hope you are doing well. I wonder if you ever found your project and puta Pontiac engine in it? I'm trying to find out if the motor mounts/perches are in the right place for a 389 Pontiac to sit right under the hood and be able to use the same driveshaft? My truck is a 66 GMC with straight 6.. Any idea?

I’m glad this thread has resurfaced. I’m very interested in the idea of going with a poncho 400 in a c10.

Best way to get a feel for the difference in the engine mount locations and orientation is to look at the differences between the engine cradles.

Pontiac V8:

https://www.summitracing.com/parts/a...CABEgIqmvD_BwE

SBC:

https://www.summitracing.com/parts/s...make/chevrolet

Personally I would go with the 400 block over any of the others. You can increase the stroke on these engines a lot with very little machine work, and this can be done in your garage with an angle grinder.

I helped my brother with his 400 build for his ‘68 Firebird. Final displacement was 461 cubes. Everyone that said it’s expensive is right, a lot more than building a sbc, even more than bbc for the most part.

Butler Performance is your best resource for a Pontiac build, and they know their stuff.

If you have a bit of money, you can end up with a better (in my opinion) engine for your truck.

If you’re deciding between a 400 & 455, go with the 400 block. It has a smaller diameter main journal and will have less friction than the larger main diameter 455 block.

Good luck and post your progress.