Clutch pedal sticking to the floor at hi revs -Anderson Ford Motorsport Hi-Rev clutch
Sounds like you have over-extended the fingers?
What type of clutch do you have...Longs, Borg and Beck, diaphragm?
The modified diaphragm, like the Centerforce have weights on the plate to tighten the clamping force (much like the longs style), while using less pressure for "lighter" resistance in normal driving. The weights make up for the weaker spring return... best of both worlds, lighter clutch and more clamp force, less slip at higher rpm.
However, if the plate goes over center, it is just as possible the weights will fight against the springs, acting to keep the clutch from re-engaging. Your shift limit is close enough to the rpm limit of the clutch (7K vs. 7.4K) to make it possible that you need to look into a different style of clutch or customizing the one you have (with greater spring pressures). You have to admit, your configuration is right at the upper edge of the line where you can still use "stock" hi-performance parts or need to start looking into custom made parts. Your days of "off-the-shelf" High performance clutch components, may be coming to an end?
Check with a couple of the clutch companies. See if they have a different take compared to my amateur diagnosis?
" ... It is dangerous to be right in matters on which the established authorities are wrong. ..." - Voltaire