Most Gen 2 trucks 01s included have rear drum brakes, but a few have 4 wheel disk (I think its only the 2500/3500 though, or maybe just the dualies?).
However the 01s do have 2 piston calipers. You can get slightly better braking with the 01 front calipers, but don't bother trying to swap parts on the drums, its just too much hassle for very little gain.
A lot of performance is going to come from the type of brake pads. If you want straight performance, semi-metallic is a must. Sure organic is low dust and cheap, but they cant take any heat before losing stopping power. Ceramic pads are nice and quiet, produce little dust and are easy on your rotors, but they cant take heat either. Semi-metalic pads will eat away at your rotors faster than any other type of pad, but you can get formulations for light city driving through heavy duty towing use.
