Tire Stagger Recommendations

I have 15x7 Cragars on front of my 74 Swinger with 215-60s I believe the backspace is 4 inches and is very close to the fender lip and rubs if car is too low
So you may run into a problem with 4 1/4 backspace. I havent tried my 15x7 with 4 1/4 backspace up front yet tho so not certain

The optimal backspace for a 15x7 wheel
front 3 3/4 inches
rear 4 1/4 inches