On this parts fiche the Bolt is the most specified component.
Parts such as the Front Cylinder Head: Clamp, Spark Plug X22e, Nut, Bolt are included in the Vl800t Boulevard C50 2005 (k5) California (e33) Front Cylinder Head parts fiche.
The most reasonably priced component used on the Vl800t Boulevard C50 2005 (k5) California (e33) Front Cylinder Head is the Washer(8.5x24x1.6).