if you crank your torsion bars you shouldnt have any rubbing with the 285s on stock wheels. i have 265s and 1.5" crank on my tbs and i can tell if i had 285s there would be no way for me to rub, the closest thing for it to rub on is the front valence. but if u decide to no crank you will probably just have to trim your valence and a slight chance some of the wheel liner but not much at all.
are you going with the e or d loads?
are you going with the e or d loads?