Triumph TR6 Slave Cylinder
At an undefined point during production of the TR6 (the specific change point was not documented by Triumph) the design of some of the internal components of the clutch slave cylinder was altered. Current slave cylinder repair kits contain parts suitable for both types.
The Lockheed self adjusting cylinder is not without its reliability issues, you can convert to a Girling system which seems to have a better track record (if you can put up with adjusting it every 12,000 miles). We have listed all the necessary components.