This Oil Pump diagram displays the required parts for the Civic 1975 2dr1200 (ka) Oil Pump.
On this parts fiche the O-ring 12.5x2.2 is the most specified component.
Parts such as the Oil Pump: Bolt,flange,6x28, Bolt,flange 6x32, Screen, O-ring 17x3.5 are included in the Civic 1975 2dr1200 (ka) Oil Pump parts fiche.