Parts such as the Transmission: Washer Thrust 25, B/brg Rad N/com, Shaft,gear Set, Sprocket,drive are included in the Cb500k1 Four 1972 Usa Transmission parts fiche.
The Transmission is made up of components including this Countershaft,trns which is the most expensive.
The lowest price component in this Transmission parts-list fiche is the Bolt,hex 6x12.