There's no single freon capacity for a 1981 Chevy Camaro Z28. The amount of refrigerant (R12, in this case, as that's what was originally used) depends on the specific air conditioning system installed in that particular car. Factors like the size of the condenser and evaporator will influence the capacity.
To find the correct amount, you must consult the vehicle's owner's manual or a service manual specific to a 1981 Camaro Z28. The information should be clearly stated within those documents. Using an incorrect amount can damage the AC system.
