Thanks for all this useful advise,
After around a 1 hour drive i did a temp reading with a temp gun on the motor and heatsink, i was getting around 170 F / 78 C... that was stock gearing 15/54.
I have just purchased the castle fan set which some people are using to mount on top of the motor and i also just brought the 16 T pinion, this hopefully should give a small speed bump and considering I'm going to have 2 fans mounted on top of the motor then this should compensate for the heat problem ?
I know you say that we don't know how powerful the stock setup is yet and if the gearing can be changed but why would have they added the easy gear mesh thing in the car which you move the pin to the correct gearing and then remount the motor, by Traxxas adding this surely they know people with experiment with optional pinions so it must be harmless ?