Hy GMONIZ, & guys, firstly I MUST say THANK YOU VERY MUCH for compiling this info. I'm a Canadian, so my info might not apply everywhere in North America. I agree with the cab groupings above, with the following exceptions, most of my experience is with large trucks, I have found cabs with two different sizes of transmission access holes in them, and cabs with reinforcements where the door post meets the floor. GMCs above the 500 series used the 324 Olds engine in 55 - 56, in 57 they switched to the 370 Olds, i'm not sure how long they used it, Below the 500 series they used the engines already listed. The 322 Buick was used in large Chevrolet trucks from 56 - 59, the 348 was introduced in 58, I have two 322 powered trucks, and one 348 powered 59. I personally have never seen a 322 in a 58 - 59 Chevy, but I have heard that they were mainly used in school buses in those years. My 59 truck salesmans data book lists the 348 and the 322 as possible power plants for the larger Chevy trucks, hope that helps.
