hate to burst your bubble, but I have yet to find a muffler that makes a 6 sound decent at high rpms. You might like the rumble of a Flow 40 or 50, but once you hit 2500 rpm, you will want to remove it. I only tried Flows, the 40 single in single out, 40 single in dual out, 50 single in dual out. I like the 50 better, but not enough to keep it on. Good luck with the search. It has been my fountain of youth, but just like that, I have not found it.

 

Maybe a e-cutout set up between the cat and muffler. I never heard one on a V6 before.