What transmission and throw-out bearing are you using? Many of the modern diaphragm clutch plates have fingers that do not "bend up" toward the tips. This is fine with a smaller diameter throw-out bearing (like we have on modern transmissions), but it can be an issue if you're using a 32 - 48 Ford transmission with the big-wide throw-out bearing.
What can happen is the throw-out bearing OD hits the diaphragm fingers in the "middle" of them - instead of on the ends/center when depressed. This is NOT how the clutch is supposed to work and can cause issues.
I recently had a well-known clutch manufacturer test their diaphragm pressure plates with the wide Ford bearing (as they were pushing me toward a diaphragm clutch).
After placing their clutch/disc in a test jig (using a 32 - 48 throw-out bearing) they came back to me and recommended that I NOT use their diaphragm pressure plates for this application.
I think they were a bit surprised when they actually tested their clutch setup. This caused them to switch me over to a Ford Long style pressure plate. They saw the issue I was mentioning when they actually tested their clutch setups with a wide bearing.
Just something to think about!
