On my 68 barracuda I run a 9"x 28" hooiser slick on an 8" wide rim with 4-1/2" back spacing, and for a street tire I run a 275/60/15 on a 8" rim with 4-1/2" back space, both fit great and dont rub at all.

1968 Barracuda 360/727 11.20 @ 121 mph 421 rwhp
1985 Harley Sportster Bobber
2006 Ram 2500 sport - The Cudahlr