yes, starting in at least '56 [maybe 55 2nd] the frame stamping was the vehicle ID number less the first [model] identifying digits - that is, it was the
year, plant, sequence number, and the door tags were made from that to match, with the particular model ID added
I've heard that there was no public documentation of that for law enforcement and insurance purposes, don't warn the thieves there's more than one ID number on the truck [cars too?] ... I believe it was '55 when the "vin" started generally being used for title purposes, which would coincide with the frame stamping change, adding a number that couldn't be removed like an engine number or door tag
Bill
