[Eagledriver]

There is a number 0 or 1 stamped on the front of the case somewhere (I don't remember exactly where, but it should be around the nose bearing to intermediate shaft cover area). If you have a 0 case then you can use zero gears or 1 zero gear and 1 one gear. If the number is a 1 then you can use 1 gears or one of each again.

In reality if you are using a used aluminum gear there will be enough wear on it to make these combo's meaningless. Just put it together and see how much backlash you have.

The fact that you are using a 66mm crank has no effect on these numbers.

-Andy