The cop car wheels on my car are ( I think ) 4.25" BS with 275/60R15's and they are very close to the spring. The also rub the inside of the wheel well on short, steep approaches. I am getting ready to order some 8", 3.5" backspace Pro Stars to put some 275/60/15 ET Streets on the car.

If you would like I can let you know how it works out. With the current config I have over two inches between the wheel lip and the side wall of the tire. My car does not have wheel well molding, so yours might be different.