I have a 51 GMC that I bought last fall. It has the 87" long bed and 8 lug lock ring rims as well as the 228 engine. On the 51s the "VIN" is really called the serial number and it's on a plate that can be found on the front part of the driver door cab. In my research, GMC didn't call out a 100 or 150 for these trucks (I think Chevy did, though). I think these are solid trucks, especially with limited rust (check the cab corners). I've been waiting for warmer weather to get mine running but I plan on a daily driver. Just brought the seat in to get it reupholstered and remove the old mouse house in the springs.
