Hey I just got a blue 2004 Mach 1, 5spd today! (9,500 miles!) I already made an appointment for Monday at the legendary CJ Pony Parts In PA to get a full exhuast system put on. I am getting a BBK H pipe, and catback exhaust. My questions are..if I get the H-pipe with the high-flow cat, rather than without cats, will it hurt my performance in any way and will it be a lot quieter? (I had an 89 5.0 GT with no cats and it sounded great but since this is newer and a different motor, it's a new story)...I want the car to be as loud as possible without being obnoxious and get the best possible performance. I prefer the sound to be more of a deep throaty rumbling sound like a helicopter =)....my next question is should I go with flowmaster catbacks or SLP loudmouth? My friend has a GT with a catless X pipe and SLP loudmouths its INSANELY loud, but it doesnt sound good....I'm confused!!!! :SNSign: