We have a 2003 F-350 pulling a 38 ft Everest 5th wheel and I have not had a weight problem requiring air bags. I did run the rig across the scale to get loaded and empty weights. When pulling I run 50 lbs air in the front tires and 65 lbs in the rear. When empty I run 45 lbs front and 40 lbs rear according to the load chart I got. I guess it all depends on how much king pin weight you have and the load recommendations of the truck manufacturer. I have empty = 7000 ttl - 4060 front and 2940 rear. Pulling I am 21100 ttl = 13960 trailer = 4340 frt - 5880 rear king pin weight 3080.
