OK, I've done it with 9398's original gears, except now with 8t and 24t in the portal axles. the total ratio is 1:11.671 So, its faster but with less torque, and still has diff. I suggest to do this, but also replace 20t w/ diff with half 12t and 20t, to give it a ratio of 1:13.897 This is an ideal 'middle' between my two tests. There are so many combinations! hopefully these explanations aren't confusing. BTW i used Sariel's gear calculator to find the final ratios.