I run 2000 in the rear and 50000 in the front on my Zero S. It uses some of the same 3racing diffs parts as the new one for the M05/06. I was thinking the same, start with 2000 and adjust up or down from there.

Jim, the new brushless motors will change the setting too. If the new motor has as much torque as you say, we might even go thinner with the oil. My diff will be here this week sometime. I am looking forward to be able to tune the back end of the M06. I noticed a big difference going from 2000 to 3000 in my VTA.