I have 71 nova with ford nine inch differential. My problems im having is finding the right backspacing. I have torque thrust II classics, 15x7 and they rub if i hit a dip in in road, so i went with 15x8's with a 4 1/2 backspace, and i have the same rubbing problem. The offsets of the torque thrusts is 0. The tires are cooper cobras, 225/70/15's, which is not a bid tire, compared to other novas ive seen. Is it possible the ford diff is wider then a gm 10 or 12 bolt Im tired of sending wheels back to summit . Anyone else run into this problem before ?