The best thing you can do to keep your drive train rolling along in stock is to add a little throttle trim via your radio... depending on the gearing and the track conditions, on my M8 I'd run anywhere between 0 and 7 clicks...
Adding weight to your drive train will make it harder for the stock motor to accellerate to the kinds of speeds you'll want ...
As far as settings on the GT7. Most people run profile 6 in stock with great success.
Some people have tried running profile 7 with the following settings:
1 kHz Drive Frequency (1 blink)
3.5 kHz Brake Frequency(2 blinks)
Standard Braking(yellow LED only)
20% Min Brake(1 blink)
TEAM ASSOCIATED -- REEDY -- SANWA -- PROTOFORM -- P1 BRAND -- TUNING HAUS -- TEAM KINWALD -- TEAM STEVE INTERNATIONAL