65 barracuda need help with rim backspacing

keep in mind - rim measurements are from bead to bead... NOT the lip of the rim... if you get a 10" rim it's 11" wide due to the lip that protrudes out where the balancing weights would go.

I run a 17x7 w/ 4.25" backspacing and have room outside, ( about 3/4 " and 1/4" inside with a 255/45/17 tire