We first changed to the MIP...From the junk 6 gear AE trans (it was inefficient) then, Associated baught the rights to the MIP unit and redesigned the diff...That was the stealth trans. Then RPM made some replacement transmissions (mainly for the Losi's) but installing them moved the motor given the same overall ratio.
Now, I'm done arguing about what we did over 10 years ago...We all knew a lot less back then and in dirt, the tracks and tires were a joke.
Physics are physics, beleive whatever you like but remember that the laws of physics don't change.