Untap Hidden Horsepower. Add some more bite to your GT's bark by reducing the amount of power you're losing to accessories and A/C. When you install this underdrive pulley kit, you'll free up up to 15 horsepower - and it's pretty much all gain and no pain, since you won't sacrifice your charging characteristics or A/C to do it. Premium Quality. Don't settle for inferior parts. These premium quality pulleys are made from lightweight aluminum for durability and performance. Made using precise, state-of-the-art CNC manufacturing, you can count on these pulleys to perform at the highest level. Easy Installation. This Underdrive Pulley kit installs quickly and easily in under 2 hours with no modifications required. Application. These underdrive pullies are designed for the Late 2001 to 2004 GT with the short water pump pulley with a bowed in face. Re-uses factory serpentine belt.