All an engine really needs to make extra power is more air and more fuel. We here at Stage 3 have a huge selection of 1999 to 2004 Mustang GT performance parts that provide plenty of both, and can have your 2-Valve 4.6L Modular V8 feeling like an entirely new machine in practically no time at all. Before you get to fuel upgrades, you'll probably need to start out with some hefty intake system upgrades like a cold air intake, throttle body, or tuner package to get more air flowing into your 2-Valve Mustang's cylinders. If you want a ton of power in a hurry, then jump right into our selection of 4.6L V8 Mustang supercharger kits or Mustang GT nitrous systems. Don't forget to stop by our ignition section to further improve your 4.6L motor's performance.