Reply to "Clutch slave cylinder"

I can tell you from first hand knowledge of the J code 302 that most likely the entire issue with clutch pressure is the change from the "original assembly line" pressure plate to an aftermarket.

As supplied by Ford in the engine assembly, the pressure plate was rated at 2,600 pounds.

If you went to buy an exact replacement for it from Ford over the Ford Parts Service counter, the "Ford rebuilt", which was the ONLY way the clutch was serviced, was rated at 2,800 pounds.

It is very close to being 100% accurate now to state that virtually ANY BRAND pressure plate is going to be 3,200 pounds.

There in lies the problem.

The car was engineered for the 2,600 clutch.

In the case of the Mustang, there is a mechanical connection, not hydraulic, from the pedal to the clutch throwout bearing lever.

In that assembly there is a part called the "z-bar".

That bar now with any replacement clutch needs to be reinforced so that it does not twist under the added load of the heavier replacement clutches.