The component with the lowest price in the OIL PUMP schematic is the Screw,cross 5x12.
Some items from this specific schematic: Pin,c0tter 30x45, Bolt,special,6x12, O Ring 17.0x2.5, Shaft, Oil Pump.
The Screw Cross 6x28 is the most widely applied product in the GL1000 GOLDWING 1977 USA OIL PUMP ( three times ).