The cranks on the small engines are all the same size. The material and quality differ through the years. The 67-70 400's were the better cranks. The newer 400 got a little weaker as the years went on.
I don't know why the books don't list the early 326, none of my did, but I remember seeing the 326 badge on the Tempest.
Pontiac parts will only work in Pontiac engines, the GMC used a Pontiac engine for many years. The early years it was the 6 cyl, then the V8. Joe
