I don't know if everyone saw this video on the other thread, so sorry for the repost. There seems to be quite a lot of debate on whether or not this does indeed suggest a V8 engine, but regardless I think it sounds pretty good.
Finally a clip that hasn't been taking down. I've been searching everywhere to try and find some sound clips from the test mules. To me it sounds like a V8 engine, and all those quick shifts seem to suggest a 10 speed tranny. There's a good chance its using a DCT.
Corvette has never really skimped out on their OEM exhaust systems, and unfortunately there are decibel limitations to what they can provide from factory. I really liked Armytrixs' system for the C7, and the fact that you could control it from your phone.