I have a couple of questions....

[lincpimp]

The mm can only handle 4s safely. Some have doe 5s, but it does not work on all. I had a buggy running a mm with a 7xl and it really did not get that hot. I would say that you should run your setup with a mm the 9xl and good batteries. A fan on the mm is needed and good ventilation thru the body is a must. Use the RC monster heatsink/clamp on the motor and gear for about 37 mph. That is my magic number. I don't think that you need to go higher than 4s, 5s will be better but you will need a compatible charger. The bk escs are not as smooth or adjustable as the mm. For a basher you really do not need 5s, just good 4s batteries and the right gearing. 35 is fast when bashing, and the electric is much quicker to get going than a nitro. You will not gwt 2.5 hp on a 9xl. My 7xl made just about 2 hp and it was almost uncontrollable. Just get some good batts and setup your system correctly.