I just spoke with Dave Z. and they have an s197 brace.
I had planned on the CHE brace, and still scratching my head why he didn't think a brace was needed for me, but Team Z will be re-installing gears and adding their brace to mine soon.
-J
I installed the CHE axel brace on my 14 gt500. You have to drill a few holes and it bolts up. I installed mine with a LPW rear cover though. I don't have the track pack so not sure on fitment with it. I got it thru van, since CHE wouldn't answer or return my phone calls.