The 8-1/4" is about 1" more narrow than the 8-3/4". My newly acquired 15x10 (4" backspace) wheels fit satisfactorily with a spring relocation and wheel opening trimming. Would probably not work with stock spring location and untrimmed wheel opening (at least with the 295/50-15's).
If you have an 8-3/4" it is 1" wider so the 15x10 would need a 4.5" backspace for the same fitment.
