rubbing tires
the 315 tires are rubbing when the wheels are cranked. The problem seems worse out in the hills than in parking lots. I have not towed anything in hills yet, but soon. I like the big tires because this is a big truck, but I do not know if I should get a 2 inch lift or get smaller tires when these wear out. I do not want to bend the fenders. I have a full ford warrenty and do not want void it.
315/75R16s are a bit big for a stock SD. Personally, on a stock truck I wouldn't go over 285/75R16s.
But, since you already have the 315/75R16 you might as well lift the truck....at least that's what I'd do if it were mine. I had 35/12.50R16.5s under a 4" lift and they fit well on the street and were okay for mild wheeling as well.
If you are worried about warranty, the only things that may not be covered are any issues that can be related to the lift and/or bigger than stock tires.
My $.02


