Parts such as the Cylinder Head Cover: Bolt, Gasket,breather Cover, Bolt 6x25, Gasket Set (nas) are included in the Gsxr1100w 1998 (w) Usa (e03) Cylinder Head Cover parts fiche.
In this schematic the "Bolt(7x17.5)" is used most often.
Check out any of the fourteen Cylinder Head Cover components enlisted.