I do not think you have made clear what year Z you have. The MSA catalog says that for the centerforce clutch you have, you will need to change to the 280Z T.O. bearing collar for 70 thru 74 Zcars. Years 74 1/2 to 78 should be all set up for the CF Dualfriction clutch.
I am the second owner of my 1972. Purchased it in 1976. Sold my 69 TR-6 to get it. Would like to find the TR-6 today and buy it back. 30 years sure did go fast. Restored the body in 1992 and painted 88 porsche silver. HLS30-66034. IZCC#9682.
Has anybody ever seen these markings on a Z camshaft before? I would like to know the grinder to contact about specs. It does not match the numbers of the main grinders like Crane or Isky etc. How does Nissan, Rebello and Sunbelt mark theirs? They do not respond to my emails.
No time or interest I guess.