Mark is great to work with, he answered a million questions and even got me a bearing that I needed and Nissan had on 90 backorder. It took my 1/4 mile time from a best of 11.4 sec to a 10.7 sec that I ran last weekend.
I am working with Quaife to build us a Torque Biasing LSD for the R230 rear-end. If you are interested, let me know.