Is your gear mesh set correctly? The easiest way to set it is get a strip of notebook paper and crush it between the gears and tighten the motor. Your mesh looks loose in the pic.
That Fusion motor/esc should be amazing. It has FOC technology like the Furitek ESC's, so it should be smoother and maintain constant torque at any speed. Where other ESC's would require you to give the truck more gas to go up a hill, the FOC ESC will keep the truck going the same speed no...