I've got a fairly well breathing H\C\I, but my car sounds even more evil now. It's a little bit different that the typical mustang exhaust setup though. I have a cam that's valve event are rather well suited to an open header environment. I noticed while doing some work under my car that my off road H was actually 2.25" instead of 2.5. I guess someone had cut the cats off, put in some pipe, and it looked just like an off road aftermarket until it caught my eye and I took a closer look a while back. I was now in the situation where I needed to get different exhaust anyway, so I took the time to figure out what would work best with my cam. The results were also amplified by my plans to run n2o in the future. I ordered a set of Summit longtubes with 1 5\8" primaries and 3" collectors. Now that I had the headers on the way, I decided to opt for 3" tubing connecting each one to a 3" Mac Flowpath muffler. So, in effect, I have longtube headers into dual 3" exhaust into 3" Macs exiting the outlet with no tailpipes. I decided to try it out without the H because I could always put one in later, and I really don't think that it needs one with the diameter of the exhaust anyway. My thoughts have since been verified by some very well known builders. Anyway, a side effect of building this exhaust that is suited specifically to my setup is it now sounds absolutely ferocious. I was expecting good, even better than the equal length shorties into off road H into 40 series flowmasters I had before, but it ended up being 20 times better than I could have ever expected. I am truly amazed by it actually and couldn't be happier with it's performance AND sound. So, if you are looking for a way to make a H\C\I 5.0 sound even meaner, I can tell you, this will definitely work. lol