out of all of the choices out there whats the best combo for HP on a 99-04 GT? dont really want it to sound like *** either but more looking for Hp than anything? and is there any full kits 2 Buy or do they all have to be ordered seperate?

 

BBK and MAC both make good headers and h/x pipes(hi-flo and offroad). as for the catback, a lot of people like to get SLP, Magnaflow or Dynomax. me, i prefer Flowmaster's on my 5.0, but, thats what alot of 4.6 owners enjoy(slp, magna, and dyno)