The most expensive part in this assembly is the Filter,rotary.
With a quantity of two pieces, the Circlip(47x) is the most used part in the OIL PUMP diagram.
Parts such as the Oil Pump: Gear, Pump Driven, Screw, Flat Fillister(22f), Oil Pump Assy, Filter,rotary are included in the Tt90r Tt90rc 2000 (y) Usa California Oil Pump parts fiche.