I tried just this center diff in my Nitro buggy. I was able to drop from 10,000 to 7,000 in oil and still not diff out at my local track. I instantly noted more pull coming out of the corner and less push.
We ran back to back tests and the new diffs were consistently 1 second faster a lap. Try going both up and down in diff fluids to get the feel you need. Maasstechidna