Can anybody tell me what kind of hp numbers i could expect on the dyno from a 2002 GT with a Magnaflow Catback, March Underdrive Pulleys, Diablosport Predator and a dyno tune?

 

maybe 15rwhp over stock...

about 235-240 auto, about 245-250 stick...

 

Really, that's it? Guy at Mopac told me they've dyno'd otherwise stock 'stangs with the U/Ds gaining 12 horses at the wheels.... but he was probably trying to sell me on 'em


Is there a better way to spend around $750 on performance mods?

 

If your looking at speed and not horsepower numbers, get a set of gears, they won't give you any extra "horsepower" on the dyno, but will make your car quite a bit faster.