I wouldn't go over 2200kv.
I swapped in a castle system into his Avalanche and its Bad ASS! HOWEVER!
It required some modification to the motor mount. Since they use the smaller can diameter, you might need to find something of similar size. IF you are feelind adventurous, you can order an additional stock motor mount. Cut the "barrel" (heatsink) off at the base. It will require you to flip the mount backwards and screw it into the motor. You just need to play with gearing.
Just remember, going too crazy can add stress to drivetrain and other parts.