Get a spare aluminum clutch, stock is plastic. I got a gallon and a half through mine and its going out.
Also if u have spare fuel tubing, cut a small bit and put it in the drive cup from the diff. It will stop the dog bones from coming out.
A new/better steering servo is always good too. I put a 645mg in mine.
And get drive shafts as well. Front and back. I managed to get mine to pop a wheelie when it hit second and shortly after on a small jump the rear drive shaft snapped.
I blew the rear diff as well. My fault, my tires where bald and not even so that caused the diff gears to give out just like it does in 1:1 AWD.