Ok....So Iused the 8 tooth pinion idea and it slowed the tank down enough for me to be happier with it. Idon't have the capabilities of video taping it in action but it is a WHOLElot less twitchy.

The funny thing is Ifound the gear in one of my son's broken toy monster trucks. They are the little 5 inch long monster trucks made by hotwheels. You push them and they keep going...I don't really know how to describe it but there was a perfect pitch 8 tooth pinion in there. It only took a bit of work to make the hole in the gear larger and press it on to the motor. After that I had to enlarge just one of the holes where the motor screws into the plastic box, enlarge the actual motor hole, and set the gear lash. All in all I have 7 bucks invested in the re gearing of my tank. Love it.