Re: Rear tires rubbing!
I bet your rally wheels are from a Corvette. Vettes had 15 X 8" with 4" backspace- ideally you should have 4.5" to 4.75". That would put your tire 1/2" farther out than it should be.
You can check by measuring with the wheel off and inside facing up - measure from the center flange to the outer wheel edge with a straightedge and tape.
As others have said, you can buy the correct rally wheels. About $100 each.
68 Camaro convertible, 6.0 LQ4 with LS3 heads, Vintage Air, 750 street demon carb, eddy perf rpm, GM hot cam, Hooker headers, 4L80e, 12 bolt, 3.55 gears