Have you poked through this thread at all?

http://www.355nation.net/forum/engi...nce-tech-questions/100290-so-you-looking-exhaust-your-i4-i5-v8-listen-here.html

 

I like the Walker Quiet flow mufflers... if you are running headers they should sound very cool under acceleration but stay fairly quiet when driving normally.

Mine had a Flowmaster (mine is 5.3L) on it when I bought it and it created alot of humming in the cabin. Maybe I'm getting to be an old guy... when I was a kid, if it wasn't really loud, that was totally unacceptable!

After getting the Walker Quiet flow it's pretty quiet except when I stick my foot in it... then it sounds almost at loud as a turbo muffla