I had the Flowmaster American Thunder Catback on my '93 GT. It sounded good and everything but the drone it had was absolutely rediculous. It would shake the living snot out of my shifter causing it to rattle like freakin' crazy. The drone noise inside the cabin was real bad too. That's what I luv about the 'Packs. They just sound mean as hell and no drone at all. Just a meaner sound at 1,800-2,000 RPM's and also at about 2,800. But I guess you just have the mufflers so you really don't have to deal with that.