I might be getting some 8"x15" centerlines for a deal for my 89 iroc w/ 8"x16" iroc rims on it. The centerlines have 4.5" and 5.5" backspacing. Will this backspacing work for me? Which ones would go on the back and on the front? I also want to know if a 295 width tire will fit on an 8" rim.