[bmercer]

Leadfoot
My car has 3 3/4" backspace front and rear, with 7" fronts and 8" rears. I was limited on the rear for width because I used a full width Lincoln Verssailles diff which is about 4" wider than the ones John used. If you have the narrowed diff, 10" should work with the 3 3/4" or 4" backspace.