The bore of my dead clutch slave is about 23.8 mm, and the length of the machined bore is about 84.6 mm. I think the nominal bore dimension it actually English units as it works out to 14.99/16". Some other clutch related parts are non-metric like the clutch gear spline, which is a standard SAE profile - the same 1 1/8" 10 spline as the T-10 four-speed in my '63 Corvette.

The casting number on the cylinder is 201 290 00 11, so it was a new design post 123 model, and I believe the same clutch slave was used on all 201/124 models.

Fastlane should have the proper part number for your car.

Duke