My heng long leopard 2a6 is in need of some upgraded gearboxes. I'm probably going with taigen v2 steel gearboxes. The question is which way would be better 3:1 with the stock motors or 4:1 with 390 motors. I want it to be faster than my tiger 1 with 4:1's and still have plenty of torque for future upgrades such as metal tracks. Im also wanting to do the same thing to my Abrams eventually.