I'll throw in on the suspension also.
My truck is a 2011 RAM 2500 CTD, CC, SB. Camper is 2006 Hallmark Ute, fully loaded. I run 3500lbs wet, so guessing camper is 2800lbs dry.
I started with airbags and regular hellwig sway bar. Too much sway with the high center of gravity, even being a popup.
Added a leaf in the rear and moved up to Fox Factory shocks 2.0 front and 2.5 for the rear (both are reservoir shocks).
Notes:
- I did leaf before shocks, it would have been interesting to have done shocks first.
- We were able to sustain 45-50 mph all the way in the Hole in the Rock road (not counting turns and stream beds; road was in reasonable condition, not worst case).
Wheels and Tires:
I am at GAWR of 6400lbs. Stock tires are fine for pavement and fireroads. If you are looking for true overland, lower psi equates to less chance of puncture. Go as far over capacity as possible (25% if possible).
Stock is 17" rim and 31" 3200lb E load tire. Toyo (and other mfgs) have higher E load capacity tires, sizes will be specific. There is not much tire selection in the 17" size. So I had to go 16" or 18" rims. Toyo M55 @ 33" is a 3700lb tire. Toyo Open Country II (285/75/18) is a 4080lb tire, this is a 35" tire.
I found some 2013/2014 18" RAM rims on Ebay and picked up a set. And put the OC II 35" tires on. This lets me run 10-15psi lower...though I think I can just run ambient in the rear without the camper.
Notes on 35" tire:
- I can not fit a true (35") spare under the truck, esp with sway bar in the way. Check spare fitiment first.
- Perhaps .5 mpg improvement on highway both with and without camper.
- I rub control arms at near full lock. 315's would probably be a different story.
A friend put the 33" M55 on his Chevy. Says best M+S/AT tire he has had in the snow. He also did the Fox shocks and is quite happy. He has a 2005 Ute.