Sounds like you are heading towards changing the gear ratio anyways, but any chance the gear boxes have been improved since you picked yours up, as everything else seems to have been as time has gone by on these tanks?

My IIIH gearboxes are quiet enough that I can hear the metal tracks operating, I would think this to be impossible as loud as it sounds like some of these boxes are?

Had a bit of noise initially, the sides of a couple of gears weren't clearanced much, but that noise seems to have really dissipated with some use. They "freewheeled" easily even when brand new.

Somewhat combining another thread with this one, if the gearing of the box is further changed from 3:1, with a motor capable of enough RPM's the torque should increase while the top speed should stay the same, correct? Along those lines, with more torque (due to gearing change) from a stop, the "squatting" effect people desire would perhaps be more noticeable.

Just offering up what little I can!