RE: mod motors in tc3
Did you mean 22/72 for the 12X2 motor? That is the recommendation in the TC3 tuning guide that Associated publishes but every motor is different. Assuming the diameter of your tires is about 2.5 inches (I just measured mine - they are 24mm slicks on standard touring car rims) 23/72 should give you a total rollout of 1.004 - the best balance of acceleration and top end.
The trick is to understand what is causing the overheating. If the motors need the comm turned that will create extra resistance which will cause them to overheat (and lose both acceleration and RPMs). If you are geared too high (if the car is never reaching maximum RPM even in the longest straight stretch) the motor will be drawing almost maximum current all of the time and that will cause heat. If you are geared too low (you reach top RPMs right away out of the corner and them just stay at max motor speed for the whole straightaway) you will generate heat in the bearings and the commutator.
Bashing is actually harder on a motor than racing depending on how you do it. When you are racing there are straightaways but there are also low and medium speed corners and braking areas where the motor gets to cool. When you go bashing in a big flat parking lot there is a tendency to hold the throttle wide open all of the time and just steer. That is a worst case condition for an electric motor. You can gear down (smaller pinion) to offset this but you cost yourself top speed.
Are you using a motor heatsink? Associated makes a nice [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXTG84&P=R]heatsink[/link] and [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXSG33&P=R]motor clamp[/link] that will help with motor heat dissipation. You can also get a small [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXKKN0&P=R]fan[/link] and mount it to blow on the motor and ESC to help keep them cool. l hope this helps.