Shecky,
I have the 15x10 Centerline Telstar 13's. The backspacing that I am running is 5 inches as my frame is notched in the rear. You should be able to get away with a 4 inch back spacing as I had a set of Cragar Street Stars that were 15x10 and rubbed the fender lip a smidge. If you roll the fender lip you will be A-OK
HTH
John Martin
1986 Buick T-type
10.91 @ 123.6
6.86 @ 100.7