Probably not going to find detailed info for anything that old. There will be several different tow ratings (GCWR) based on factors like engine, transmission, 2WD/4WD, rear axle, and bed length (wheel base). If he is talking about a travel or utility trailer, I would guess no more than 5000 lbs, and even that may be stretching it for an old suspension and drive train. If he is considering a 5W, I would just say "No way". The payload is as much a limiting factor as the tow rating.