Spec Stage

What Mod should I get for my 2003 Mustang GT next?

I want to spend 300-400 U.S. dollars. Right now I'm off-road H-pipe, flow masters, Cold air intake and a Stage 2 Clutch Spec. What do I do next?

Under-drive pulleys $ 100-150 8-12hp super chip programmer good big mod 280-400 Dollars to get the most out of your Gears mod by far the difference greater sense of power for money 3.73 s to 4.10 standard for the automotive about $ 300 installed and 450 headers-15hp 250-400 $ 7, will help to breathe better exhaust sticky tires for drag racing, $ 250-350 enormous difference to a complete song, sometimes dramatically improve a car

335xi: SPEC Stage 3 Clutch and Lightweight Aluminum Flywheel