On this parts fiche the Screw,cross 6x40 is the most specified component.
The component with the lowest price in the OIL PUMP - OIL PRESSURE SWITCH schematic is the Screw,cross 6x40.
A sample from the products for the Oil Pump - Oil Pressure Switch include: Screw,cross 6x40, Chain,oil Pump, Circlip, 11m/m, Pump Assy.,oil.