will 275/60/15 fit 71 Duster ?

No, I bought 2 15x7 Keystones that were made with sbp centers for the rear......and I am using 2 of the 14 x 6 or 7 Keystones for the front with 205-75-14......I may have the 14's made into 15x6 in the future,,,,,I prefer skinny on front, wide on rear