I am resurrecting this thread.
Attached is the picture of the '73 240z in May 2013.
Today after maybe 60k miles, the car still looks the same engine is pulling harder than ever, but we need a new Transmission and Rear end. After consulting with my son, I believe we are going to go the Subaru R180 LSD route for the rear end. For the transmission, we are planning to go to the CD009 or the 240SX FS5W71C depending on what we can find.