ORIGINAL: invertmast
KC,
not sure what gyro you are using, but all the gyro's i have in my heli's (spartan, futaba 401, futaba 240, futaba 601/611, JR 7703d) are all able to be used with 6v systems. Its the Tail rotor servo's that are limited to 4.8v only.
i've got the matched pairs JR G5000T/8700g