tire / rim

Newbe here, I don't get on here much, but I have a 73 swinger bracket car and I just completed moving the springs inboard. I would like know what wheel and slick combo I can get away with. The car has a 9 inch ford rear, not a mopar. I looked at the wheel tire combo's on this site, but I don't think some of the combo's will work as I have the 9 inch. I need to know what backspace you guys are getting away with. Thanks....