Also make sure that your engine is perfectly straight when you put it in because I was blowing clutchbell bearings every day because it wasn't perfectly straight.
Yup, well I'm taking out the grease and putting silicone oil in. Why would I only do one of them? This way none of the diffs will unload as easily.
Grease just helps prevent wear on the gears and just some is applied on the gears. Silicone oil, aka diff-lock oil, is fills half of the case of the diff. It actually slows down the diff movement in the diff so that not all power can be unloaded at once. It helps to "lock" the diff a little. Some people acually lock up the center diff completely, so it is similar to an ST drive train. Just tring to clear things up a little. Please tell me if I have this wrong.