I'm running 14x8 cragars in the back of my 65 barracuda with 4.25 backspace. Fronts are 14x7 and I can't remember the backspace for the fronts. But with the backs I could run a 245/60/14 but would rub with passengers. Has 235/60/14 now and no rubbing. Fronts I've ran anywhere from a 185- 215/60/14 with no issues
