i know back in the day when our cars were built each division of GM (Buick, Pontiac, Chevy) all had different engines, but what i was wondering is did GMC have there own engines and blocks or did the trucks just use Chevy blocks.
Thanks for the info in advance
-Doug

 

You didn't number the cylinders. The old sixes were different between the jimmies and the chevys.but when the bent eights arrived on the scene the jimmies engines were all borrowed,from pontiac for a couple of years and from 57 or 58 on they're all chevys.
The $75 difference between the identical chevy and gmc was lockwashers! Jimmies had 'em,chevy' didn't!
Ron

 

What were the lock washers used for?