If your need to fine tune the wheel tire combo on your 79-93Fox Body Mustang then a pair of 8mm Wheel spacers may be just what you are needing. These are four lug design so they fit stock applications and will work on aftermarket wheels needing that little extra room to clear brakes or suspension. Light weight so these's no reason not to bolt on a set and get everything moved out just right.
I have been ordering items from Latemodel Restoration for many years. I've found them to be exceptionally professional, timely with order processing and shipping correct items ordered. I've never received an incorrect item on an order.