My dad and I are going out to get a 94,95 GT.Performence wise we're going to put on equal lenth shorty headers,a cold air intake and replace the mufflers(mufflers only).I want my car loud and throuty but not obnouxisly loud and.But I still want to hear the car during idle,accelaration,and cruising.So can you guys reccoment a muffler?I also want to put a shifter in so what shifters are good ones?And 1 last question if I put a GT40 or edlebrock performer or performer RPM upper/lower intake will i need to port or replace my stock heads?