FWIW I have put Dynomax Super Turbo mufflers on both my Troopers. If you get the 20" body models, they have a nice mellow throb at idle, you hear them on accel, but they are pretty quiet at cruise, you don't even notice it. The 14" body models are too loud, pretty much like the PV.

I put the 17748 model on my Troopers, it has the 2.5" pipe size which is good for a 3.5L.

http://www.dynomax.com/ecat/pdfs/superturbo.pdf