[Musclerodz]

You need to tighten the bolts every time. If the frame has a sag, the body will sag and it will never be correct. Get another set of plain nuts to check everything with. Nylon lock nuts are designed to be one time use. If the rubbers are all correct, and everything is locked down, shim the body whatever it takes to get it correct. The manual does not account for 40 years of abuse when it comes to shimming the body.

Mike