Same caliper and pad, but the rotor is larger AND VENTED.
That does make a difference. The larger rotor allows more braking torque due to leverage not to mention the ability to cool better due to being vented.
GT and V6 brakes are the same, and use puny solid 10.5" rotors
it depends which cobra wheels he has. if he has the stock 96-97 corba wheels, it will not clear. the 98 cobra wheels clear however. the 2000 cobra R used a 98 cobra wheel for the spare tire. thats what i will be getting for my spare.
Lest we forget about loosing the ability of parking/e-brakes. Of course you could do the Ferrari setup and have larger calipers mounted on the front of the rear rotors and a little park brake caliper mounted on the lower rear of the disc...