I've currently got some old firestone 205/70/14s on standard magnum 500 rims. The 205/70/14s should have a section width of about 8", on a 6" rim. Any idea what the rim size and back spacing is on standard Magnum rims, I'm guessing 15x5 or 15x6?
No idea what the backspacing would be though?

Oh, and I've got 2" clearance each side of the wheel....