I had a 2008 2500 dodge. I put Firestone air bags on it. But first I read the manual. What I figured out was I already had a 3/4 ton suspension on the truck holding the weight of the camper. I don't recall now the exact numbers but the manual said x amount of air pressure supported x amount of weight. It worked out that if I ran with about 22 lbs in the air bags it supported the additional weight and towed level. When winter came and the camper was not being used they got aired down to 5 lbs and the tires went down to 40.