Parts such as the Cylinder Block: Bolt,sealing,20mm, Block Assy,cyln., Bolt,plug Drain 14mm, Washer,sealing 20 are included in the Gl1500 Goldwing 1990 (l) Usa California Cylinder Block parts fiche.
In this schematic the "Dowel,pin,12x20" is used most often.
The thirty-one Gl1500 Goldwing 1990 (l) Usa California Cylinder Block component parts are all listed in this schematic.