2006 Dodge 2500 to 2015 Ram 3500 pin height

My new 2500 is noticeably taller than my 07 3500 was. Roof and bed rails.

Just a thought but my 06 3500 is 58" from road to top of tailgate. Might measure yours while you still have it and go to dealers lot and measure the new ones. Kind of a moot point though as our springs are different. I'll have a good 4" of squat with the RV on it, YMMV :W Bottom line is the new Rams aren't that much higher than they were 10 years ago although the suspension could very well be stiffer resulting in less squat and hitch adjustments being needed.
Congrats on the new truck.

I had a similar situation. I had a 2002 F350 supercab long bed 4x4. I now have a 2013 f350 crew cab long bed 4x4.

I bought the new truck, installed the rails and dropped the hitch in place. Everything sat the same. I didn't have to make one adjustment.

The fifth wheel tows 1/2" high in the front. I have over 6" of clearance from bed rails to 5th wheel overhang.

I was worried I would have to make major adjustments. It was all for not.

My neighbor has a '08 2500, and I have a 2014 3500. My bed rails are noticeably higher. I'd say 2-3 inches, but never measured it.