I am curious as to where you got the inspiration for this center diff setup.... As I have a very similar setup (minus the awesome carbon fiber work) in my Maxx. And I'm not trying to thread hijack here, just wondering if you got your idea for the center diff setup from my Maxx.
Anyway, here are some pictures and a vid from my build thread that I posted here on RCM and Traxxas a few months ago (not nearly as nice as yours, but the same setup basically) -