I have the old E widemaxx before and also installed the previous HV-Maxx 6.5 version. I am using 2 6-cells then, but the performance from the stock titans is way much better. I did not change anything inside the 2 speed transmission, but the only modification I did with the stock spur is add friction pegs to make all holes complete. My whole front and rear driveline are spec'd T-Maxx 3.3 revo axles. The whole thing is holding up, except for the stock center half shafts. But I never got into changing them to 3.3 spec also, since the new E-Maxx came out, sold the whole ride locally and fund it on my new purchase.