[DanEC]

Or there could be too much free play at the top of the pedal before the TO bearing makes contact with the pressure plate. You should not get much perceivable movement if you grab the end of the fork by hand and try to yank it rearward, before it is stopped by the pressure plate fingers.

Also, I own an old Corvette too and they have a shallow foot box and limited room for clutch pedal stroke so to get full release of the clutch and a bit of free play when released, required careful adjustment. They have lots of problems with clutch discs that don't release with the clutch pedal fully depressed. One of the experienced mechanics on Corvette Forums started setting a variety of pressure plate/disc and flywheel assemblies up in a hydraulic press with a dial indicator. He then measured how far the TO bearing had to be pushed to fully release the clutch disc (.050" clearance). He found out there is a lot of variation between flywheel manufacturers. Some were so bad they just can't be made to work in a old Corvette. McCleod clutches were generally very good. Some of the favorites like LUX and Centerforce were iffy. So, could also be a problem with your pressure plate depending on the source and style.