VLSD, which one do I have?

So I am doing some research on LSDs. I've heard that some S13 240sx come with VLSD, not sure about the S14. I was originally told that the S13 240SX Hicas modle has a VLSD. Is this true? I want to confirm since I have a Hicas.

I also hear that the J30 has a VLSD that is a direct bolt up with in a range of years, as long as they have the same ammount of bolts on the axels.

Is there any difference between the J30 raito on the VLSD compared to the VLSD on the 240sx?