Parts such as the Crankcase: Stud, 10x153, Ring-bearing Setting, Bolt,flanged,6x40, Nozzle are included in the Kz750n2 Spectre 1983 Usa Canada Crankcase parts fiche.
In this schematic the "Stud, 10x153" is used most often.
Check out any of the twenty-four Crankcase components enlisted.