brushless conversion help!

[CerberusVI]

Ran the motor tonight, feels a little down on power. after 7 mins the motor hit 200f again. due to the size of the motor i cant gear down anymore than i am now. I might be able to go to a 18 or 19 but i don't think it will drop the temps enough to make them reasonable to run.

So now i need help with planning a new setup, I was thinking of a castle 1515 2200kv motor. using the setup calculator if i geared for 40mph on 6s the motor would be around 49k Rpm which seems really high. I'm pretty set on 6s as i have already purchased the battery