g50/50 questions

[pavulon]

Trying to do some home work in preparation for potential 930 purchase. I've narrowed my considerations to the '89 930 primarily for the combination of original 930 apperance and near maximal 930 evolution (right or wrong that's my train of thought). All constructive comments are welcome but I have these general questions not related to any one car out there.

1. Was limited slip standard issue on all '89 930's?
2. What is the "%" slip on the '89 930 differential and what does that imply?
3. On average (difficult to assess but please humor me), how many miles will the G50/50 go before needing a rebuild?
4. How much for a new or rebuilt G50/50?
5. If it was yours, who would you trust to do your trans rebuild or sell you a new one?

Thanks in advance for any information provided.
-Scott