Atwell was asked:
Do you have a reference or knowledge of which Spit master clutch cylinders (3/4 or 7/8) went with which clutches, which release lever pins (long/short), which slave cylinders (long/short)? Seems there might be a lot of different pieces not properly matched in today's catalog offerings.
I did some research last night and came up with the following information. I was right about the "dividing" point being coil spring v. diaphragm clutches.
Trouble is, I don't know which is which by bore size or by construction (alloy, cast whatever). Part numbers are as follows:
110762 (Triumph) or 3010166W (Girling) for the coil spring clutches. Takes a Girling SP2001 rebuild kit; works with the 207907 release lever.
144716 (Triumph) or 64068370 (Girling) for the diaphragm clutches up to 1977 or so. Take a Girling SP2348 rebuilt kit; works with the 213032 release lever for the three-rail gearbox and 129412 for the single-rail box. There is a Girling 74066168 slave cylinder apparently used from 1978 on; takes a SP4191 kit. I don't know what the difference is from the earlier one(s), unless it has metric fittings or something like that. As for the pushrod between the slave cylinder and the release arm, that appears to be the same p/n (109182) throughout the Spitfire run.
All of the above is taken from several sources, including original factory spare parts catalogues for Herald 1200, Spitfire 4 and Spitfire Mk. 3, a Leyland "fast moving parts" book, TRF and John Kipping catalogs, and a bit of online browsing at Rimmer Bros.