40 series or super 40 flows

[raidermanny]

I am getting ready to get my exhaust done and can't decide between the flowmaster 40 or super 40 series. I was talking to a flowmaster rep at the last good guys show and he said there is no difference in performance between the two, just sound, even though the website says different. Has anyone heard the super 40's? So far those are the ones I'm leaning towards. The flowmaster website has a sound clip for both but they are on two different motors so it's hard to tell. Any advice, suggestions are appreciated. This is going on a 450 horse 383 with Hooker super comp headers.