Great, thanks for the reply and information. It looks like according to that brake chart my truck may have been ordered with JB7 and the 6800lb GVWR. I really appreciate the help!
Hey everyone, longtime “guest” reader here and I have learned so much from here, so thanks for having an awesome forum. I have a 1979 K20 with a 400sbc, TH400, NP203 that I am working on. Unfortunately the SPID is missing, I’m in the process of ordering an RPO list for the truck. The truck...