[Alan's Classic]

I would level the center section. Picture a square under the cab from cab bolt to cab bolt. But level the frame at those points, not the cab bolts (mounts). Once the center section is level from side-to-side and front-to-back then do your comparision measurements on a level floor. That will show exactly what is going on. I thought I had a frame data sheet showing the heights at different points on the frame, but I don't.