LT1 Clutch Issues
A spongy clutch pedal is usually caused by air in the hydraulic system or it could be just an excessively worn friction plate.
I would start by bleeding the system. Once that's done, if the problem persists, check the travel of the clutch fork by removing the flywheel cover plate and have someone press the clutch pedal to the floor. If travel is at least 11mm (0.43"), the problem is not with the pedal or hydraulic system.
1995 Firehawk #528 resto-mod underway
Planned 383 rebuild: 195cc competition LT4 AFR heads, custom cam grind (still debating specs), 6" or 5.85" rods, forged internals
Upgraded T56: Viper mainshaft and 2nd gear, steel 3/4 shift fork, Billet keys 1-4, bronze shifter cup, internals Cryo'd and REM'd