[lincpimp]

Since you will be keeping the 2 speed and mech brakes and 3s lipo, may I suggest a feigao 8l. It will allow decent speed, 35mph plus, with normal gearing. 40/16 gearing will be fine and will most likely run cooler than the 7xl. The 8l with 3s will turn faster than the 7xl, and the mm will most likely see a lower amp draw with the 8l. Because you would have to gear the 7xl higher you place more load on it, causing a higher amp draw. I have personal experience with the 8l on 3s lipo in a revo, and it ran fine with good temps. plus it is 10 bucks cheaper. It will also be wise to run a ubec, it will help the mm temps.