Quote Originally Posted by vht View Post
I put super 40's on my chevelle, flowmasters, with 3 in out the back. Sounds awesome around town, drives me crazy on the rd at 60 mph. I think if the floors had some better insulation it would help.
Your 60 mph problem sounds like it could be a tailpipe problem. Did you take your tailpipes all the way out the back, or at least to the outside of the body, to exit away from the underside of the car or are you running short pipes that end under the car?