I use a 9.5t motor with the stock esc that comes in the ready to run.
I got the speed passion one so no soldering is required as you just pull the motor tabs out and plug the new one in.
http://www.rcmart.com/speed-passion-...cPath=1560_946
I havent raced with the new motor yet, that will be done on the 7th but I have done some testing on my street and in my garden and temps seem okay, nothing excessively hot, just warm. And I dont have any cooling holes in my shell..
But I have noticed a positive difference in performance though and is a lot better than the stock motor