Please help a fella in need. I want to order a set of 15" Cragar Drag Lites for my 89 Firebird but I have no idea what backspacing or width or bolt pattern that I need. I really want a 10 inch wide rim but I dont know if it will fit (I dont want them to stick outside of the fender wells). What is the widest rim that I can get inside of my 89's fender well and what backspacing will I need? I also want a 7 inch rim up front so what backspacing up there?

THANKS IN ADVANCE