This Cyln Head Comp,re is the most expensive of the items that make up this Cylinder Head (rr.) assembly.
Some items from this specific schematic: Bolt,flg.soc,6x40, Washer 5mm, Plug,spark(cr9eh9, O-ring,7.8x2.2.
The most reasonably priced component used on the Vfr750r Rc30 1990 (l) Usa California Cylinder Head (rr.) is the Screw Cross 5x8.