That is 100% Factory-issued stainless steel exhaust right there. You have a newer model, and the stroker engine, so GM might have put a different muffler on. If you are really looking for a nice beefy sound on throttle, but quiet at idle and highway with little resonance, I'd go for a Magnaflow or Corsa. Those two are prohibitively expensive for me though. You might look at Hooker Aerochambers or some of the mufflers Spintech makes. Both are good choices.
