Parts such as the Water Pump: Pump Set,water, O Ring 27.6x4.1, Packing W Pump, Thermostat Unit are included in the Civic 1979 (z) 3dr1200 (ka) Water Pump parts fiche.
With three applications this Bolt,hex 6x42mm is the most specified part.
The component with the lowest price in the WATER PUMP schematic is the Bolt,flange,6x12.