Tim is right. Basically they changed everything so that the crossmembers unbolted and transmission could be removed from the bottom of the truck. That affected the brake line routing, starter is different due to electric start vs. the old foot stomper. Carb had auto choke where manual trans had a cable operated manual choke with a throttle cable also. GMC had different linkage, frames, and shift indicators than the Chevs did. Truth is, the GMC looks a little more substantial and the shift indicatpr is much nicer than the Chev version. In half ton trucks, GMC got hydramatic I think in 53 where chev waited until 54. Tim is being modest. You need to look at his website to get a feel for all of the information he has accumulated. I learned quite a bit out of neccesity by biting off a project that turned out to be bigger than I expected. All taht being said, I don't like to see any of those parts get away. As Tim also stated, there are many hydramatic owners on the oldgmctrucks site. There will be several people willing to help you out to keep an eye on where the old parts go. Good Luck, G.H.
