i will be using 2 inch spacers if i decide to put 285's on also!

 

i have 315/75/r16 and they dont rub n mine at all but like said earlier thats not the problem. Get a leveling kit and 2in spacers n the back and you should be fine. I know a guy that hae 315s on a ford dually n it did just fine. but i dont know how heavy of a load you are pulling but...personally i would put 305s on it to be safe