Heck, I'd even go with a Traxxas Velineon motor if you're running 3S. IMO, it's a better motor than the Mamba Max motors. You should be able to pick up one new for ~$60-65 on eBay.
ok i forgot to mention it will be on 2s tp extreme 5000 batt, is it just me or does it seem like the 380 would be a bit small for a truck, maybe i am wrong
For 2s, I would say a 6s or 7s 540 feigao. They are more powerful than the mamba max motors.
On a side note, I have a 540 6s motor that has 1 run on it. PM me if interested. It has a kv of about 6000 and you could gear it to what ever speed you want in that truck. It is lower kv than the 7700 mamba motor, but it has a longer rotor and will produce more torque than the mamba motor and will run cooler.