Clutch Diagnosis Help Needed

[wrogers55]

I'm looking for an easy way out of this, but I suspect I'm in for a long weekend. Clutch slipping problem. It's been fine for over 500 miles I have had the car, a Backdraft, 418 sb, FI, putting out north of 540HP. Problem started with a very light slip in 4th gear from about 3000 RPM, only for a second or less then it would stop slipping. Such a small slip, it was easy to mistake for wheel spin, which this thing will do whenever it gets good and ready.
Real problem started when a 2nd gear run up caused the clutch to just let go when the motor got up on the cam and the clutch slip let the motor instantly redline. I immediately backed off and it grabbed and I made it home fine. Man, what a smell. Now, for some diagnostic help beyond just adjustment. The pictures show the clutch fork tight against the shield and no free play by hand. The internal pictures show the bearing against the pressure plate fingers. I don't see any way to get free play in the fork. The Ford setup is new to me, but it appears something has gone wrong at the other end of the fork or maybe this is the way it behaves when the clutch plate is gone. Any help would be greatly appreciated before I start to pull this apart. Wayne in Gilroy, CA