I have a 331 with BBK 1 3/4 longtubes, Offroad h-pipe, and I had the flowmaster 2 chambers with the pipes cut off so it dumped right out (I wish I never did that by the way...) I got a loud exhaust ticket THAT SAME NIGHT! The noise was rediculous, way too loud. I went to AutoZone, had them look up mufflers for my 1990 GT and it had a 2.5 inch option. He got me 2 mufflers that were made by CherryBomb? and they were called turbo II's? Anyways, they were 19.99 each. I bolted them up with no pipes coming out and it now resembles the feeling I get when I ride in my buddies C5 Vette! Loud, but not rediculous. I really want pipes back on my car. I hate the drone. But I will say, it did help. I can't tell the difference in power either! Just my 2 Cents.