Sorry for Underestimating your Knowledge (Got Carried away)

For the Diff I just bought the parts and built up a new one then swapped it out (But then again it was my First Diff Rebuild)
The local word on Diff builds is pack the Cup full of heavy greases, this loads it up so it doesn't diff out as much.
It is also generally stated that you pack the rear diff with heavier grease than the front.

I personally can't say I can see the difference, but I may have used grease that wasn't heavy enough. (There was some info when I asked the question in the T-Maxx thread.)