My brother had a 10" rim on his 72 and if I remember right it had a 5.5 inch backspacing with a 28x10 tire. On my 68 I have a 8" rim with a 4.5 inch backspacing and I have a M/T 295 drag radial on it but I have about 2" of clearance on the inside. The company that makes my rims don't make the right offset with their 10" rim. Good luck.