4.25" will bring the wheel even more to the frame-now being about 1.25" in from the outside,the way i would go if you can get the size would be= 15x7" rim with a 3.5= backspace and a 15 x 8" rim in back with a 4" backspace-this would have the center of the rims perfectly centered and the fronts only 1/2" in from the outside and the inside alignment.the stock gn rims are 4" backspace on a 15 x 7 " rim. the reason i stayed with a 4" backspace on the 7" rim is if you re are ever gonna upgrade to a larger brake and rotor with tubular a arms -this system actually will bring your wheels out about 1/2" in the front,there by making the real effective backspacing 3.5" on a 7" rim keeping it truely centered with the rear wheels without having any rubbing problems or the wheels looking out of alignment.HTH