Novak says the GTB is safe down to a 3.5T motor (prob cause that is the lowest turn motor they make), so I find it unlikely that the 3T equivalent motor is going to cause you an issue on the GTB. Just be sure the fan on the GTB is in good shape and running.
If you can put all that power down, you are likely going to find other weak points in your car before the motor causes the ESC to get too hot. Be sure to use high quality connectors, if any, and use 12-gauge wire throughout, otherwise the wire itself will be acting as a resistor and heat up, including making the motor and esc run hotter.
What kind of racing are you doing that you NEED a 3T motor?