I just installed this kit on a customers GN and the 11 inch version on my car a few weeks ago, it saves some weight due to the thinner rotor and aluminum hub, calipers and bracketry. The 12" definately wont clear stock GN wheels, they JUST make it with 16" gta wheels. The 11" kit should clear 15s. Braking performance with the 11" on my car was similar to but slightly better than the heavy blazer brakes i removed. Install was cake as long as youre good with a hacksaw and can drill and tap accurate holes. Also noteworthy is you will need to pick up some 1/2-20 lug nuts, the hubs use 1/2" screw in studs. For the price vs weight savings im very happy with them.