I recently bought a '57 GMC V-8 4 speed w/NAPCO 4-wheel drive. I'm told a pontiac motor was used but having trouble getting basic details of the engine. What cu. in.?? any other info???
The '57 GMC V8 (in the smaller than 2 ton trucks) is basically a '57 Pontiac 347 cubic inch engine. The main differences are: The GMC uses a deeper dished piston reducing the compression ratio from Pontiacs 8.5:1 base engine to 7.8:1. GMC rated the engine at 207 horsepower. Pontiac rated theirs at 227 (I think). GMC used a Bendix-Stromberg 2 barrel carburator. Pontiac used a Rochester 2GC. The carb on the GMC sits on a spacer about an inch high to provide room for the throttle linkage to swing that is not needed on the Pontiac. Other than that the engines are pretty much the same.
