mkirsch wrote:
The issue is, it's not physically possible for the bed to be the same depth front to back, and the camper to be the same depth front to back, and there be a difference in gap along the frame rails, unless there is a structural concern.
I agree. If the bed rails measured the same height in the front and the rear, I would start by rechecking and then checking the height in several locations. I would level the truck bed and then check to see if the rails were level. A 4' level or even a straight yardstick could be used to check for any crown in the truck bed. I would next check and measure the camper overhangs from the base of the camper and do so in multiple locations.