Parts such as the Cylinder Head: Clamp, Bolt,8x146, Bolt,6x46, Washer-plain,8mm are included in the El250b3 Eliminator 1989 Usa California Cylinder Head parts fiche.
In this schematic the "Washer-plain,8mm" is used most often.
The Cylinder Head is made up of components including this Head-comp-cylinder which is the most expensive.