There are many variables to this question about what oil to run but in my experience 10K is way to heavy. Depending what track I run at I run 5K,5k,2k or 5K,7K,2k and some times 7k,7k,2k and this is subject to change for track conditions. I do not even have any 10K. Do you understand how a diff works and the purpose of having them? The thicker the oil the less limited slip you have.