it maybe in the Hyper-Rev book, though I couldn't spot the Z. I don't think they still have the Z though... it may be a customer's car. When I spoke with him last week, Mr. Kitabayashi recommended the Tomei LSD, which surprised me since Tomei was supposed to only make the R200 LSD for the NA, no R230 LSD for the TT. It may be a custom order item. He also recommended the OS Giken cross mission. There was no mention of changing the rear end ratio... could it be referring to the taller OS Giken 5th gear?