I have a 51 GMC one ton long bed stepside with a dump. The bed sits on white oak rails. I am including some pics that I hope will assist. The dual ram lift has a framework that the bed bolts to along with thru bolts with the excentric washers that extend through the oak with counter bored holes on the underside of the oak to accommodate the nut, lock washer and flat washer. The bolts are cut just shy of the bottom of the oak rail so they don't hit the metal truck frame. The oak rails are relieved for any bolts or rivet heads in the frame so the oak can sit flat on the frame. The oak rail is 2" high and 4"wide.The rear of the frame was clipped on an angle and the box pivots on a pipe. If you desire I can get a few more pictures and dimensions. Because of the dump there is no rear bumper and the running boards, usually bolted to the fenders, have been unbolted and slightly hammered for clearance.Hope this helps some Ricster
