Sorry I dont have the exact answer that your looking for but I am sure you can go up two teeth with out any issues.
Your best bet is to temp your esc and motor and as long as it dosnt vary that much from stock you will be fine.
If you go too high you will burn out your esc and can damage the motor.
Original RC 10T, T4, RC8Te, Tekin RX8. Losi Ten SCTE, Slash 4x4.