I wouldnt change the gearing unless you are going to step up the voltage and run a 4S. You can keep it at 3:1 and change to a 16X8. As a matter of fact, I recommend it as the 16X10 is not the most efficient prop on this setup. However it is what I have (3 of them to be exact). As you move the gearing higher you have to either step up the prop size or step up the voltage to maintain the amps and watts. Kind of like having a BMW in 5th gear with the pedal pegged to the floorboard...then all of a sudden you shift into 7th (if there was such a gear), but the car is giving you all it can with the max horsepower provided....the car will start to slow. Now if a supercharger were installed to give it another couple hundered horsepower to push those extra gears.....Vroooom.

-Mike