Just stripped the Spur gear on my slash and saw that the ultimate came with a center diff so I installed it and the car runs so much quieter but my question is this: The instructions say not to run 3s lipo due to heat. Ive got a 3s 11v 5000 mah batt, any long term success running a 3s? Should I just repair the spur on the slipper if I want to use 3s?