Parts such as the Rear Swinging Arm: Bolt, Upper, Arm,rear Swing, Pin 20x20, Bearing(22x29x30) are included in the Gs450l 1980 (t) Usa (e03) Rear Swinging Arm parts fiche.
On this parts fiche the Nut, Lower Lh is the most specified component.
Of all the components used in this assembly the Absorber Assembly,rear Shock is the most expensive.