Of all the components used in this assembly the Valve-exhaust is the most expensive.
Parts such as the Valves: Shim,t=2.40, Shim,t=2.25, Shim,t=2.35, Shim,t=2.85 are included in the Kz750b4 1979 Usa Canada / Mph Kph Valves parts fiche.
The component with the lowest price in the VALVES schematic is the Collar,valve Springe.