Looking for ideas with bedrail clearence on 2013 Ram 2500

Well it's not perfect but I've seen a lot worse. For what its worth I ran around for 2 years with only 4" of clearance and never made contact. Just had to watch some of the driveways closely. I finally made some hitch and pin box adjustments to get me to 6".
I agree in that those rear tires are going to be the 1st ones to go south.
You have a photo of just the hitch setting in the bed?