Ball diff? Then buy the TA03 one and build it exactly as per the instructions. Only difference? Use anti-wear grease instead of the standard diff lube supplied. Don't take out bits or anything, just build it. The only other thing we're going to change here is when you tighten it. Just...umm..tighten the crap out of it, and leave it.
That's all you need to do, there's no science to it,