[rsk289]

Wow. That is the exact same fork (allowing for minor measurement variation) as the one that was on my '68 Mustang. I'm beginning to think it probably wasn't the original Mustang fork as it doesn't look like any in the catalogues. Thanks Dan - I will use this and lose no sleep over it now.

The dimension of the Daniel Carpenter C5OZ arm from pivot to fork tip bearing surface is a little less than 3 3/4", but the end tips of the fork are much shorter and the release bearing springs are not retained by this as shown in my first picture. With regard to your last comment regarding the point on the input bearing retainer where the release bearing sits when in action, my photo is taken with it in position judged by measuring how far the clutch fingers sit behind the rear block facing. It would move sightly closer to the engine when the clutch is depressed.
This arm is too short - I'm very happy I have the older one! If only Ford had stamped with a number, I could tell what it's original application really was.

Looking at your photo, Dan, the CSX2551 fork has the same tip arrangement as the Sunbeam Tiger, for the circular spring. Odd.