Here's some video someone posted over at Camaro5 from the Eyes on Design show a couple weeks ago...nothing exciting, just our Y-Camaro idling (and mom waving at the end!):
https://www.youtube.com/watch?v=aGAoa0F39r0
I can't remember which muffler I went with either, but I'll guarantee you if you ask the folks at Pypes which muffler the yellow Yenko Camaro that helped them test the system is running they could tell you.