The 5/8 to 3/4 low on the passenger side measurement was from the ground. The cab mount clearances are as follows. RR-1.82, LR-1.87, RF-1.94, LF-1.92. all measured with an inside mic. The only thing left to change on the frame are the front springs. I did not change them when I rebuilt the frame was because I could not find any that were broken. Is it possible that they may be weak enough to cause the cab to be low on the passenger side?
Red