On my SR-71 I just replaced my Group C racing brakes with Wilwoods - 6 piston fronts and 4 piston rears - with slotted rotors. My old set had cross drilled all around from Nissan. Those that say the rears don't make much difference probably haven't experienced a serious setup. And you're right, they look better also. Got mine from: russell.seibert@verizon.net.