The 7700 is meant for 1/10th scale trucks/onroad vehicles, not monster trucks. Since the e-maxx is a monster-truck it's not an option. the KV value of the motor is too high, and the torque isn't enough.
I suggest to read the sticky in the brushless section i wrote, it would explain quite a bit.
Bytheway; if you have got a question, you don't need to post it three times.