Opinions from 4x4 dually owners on tires

I agree with Boatycall. Previous owner was probably just interested in drawing attention to his fat butt by making his fat butt fatter ... er ... his truck's fat butt. I'd take it back to stock tires as I see no practical advantage to the wider tires. Stock tires will have plenty of capacity for your camper, will better accommodate standard swingout brackets, and keep your overall width down. If you have to buy new stock rims you should be able to recoup some if not all of the expense by selling the 315 tires and rims as I'm sure the nonstick items weren't cheap! If narrowing your rig even further is desired then super singles would be an option but they won't be cheap either.