Can you put clutch disk in backwards 1984 Chevy truck?

No, you cannot install a clutch disc backwards in a 1984 Chevy truck (or any vehicle for that matter). The clutch disc has a specific orientation with the friction material facing the flywheel and pressure plate. Installing it backwards would prevent it from engaging properly, likely resulting in no clutch function at all, and potentially damage to the transmission, flywheel, or pressure plate.