I'm running 255/65/15's on the rear now with a set of ol 80's camaro wheels with i'm pretty sure 4.2 backspacing i got a lil tire rub on the fender wells from dips and stuff from the road. So I'm assuming with the 2" drop and a set of 255/50/17's I'm gonna be in the same polished fender spots, so I guess I've answered my own question.