I bought a almost new stampede 4x4 for $100 and converted it over to a LCG slash 4x4. Installed a castle mamba pro and will use the velenion motor and esc for my basher. This LCG slash will be used for racing only. What diff oil weights would y'all suggest using in the front and rear diffs?? I was thinking 30k in the front And 50 k in the rear or would it be better 30k rear and 50k front. Also I installed a center dif... What oil comes stock in it??