Parts such as the Crankshaft - Piston: Piston Ring Set (4th O/s), Connecting Rod Assy, Piston Ring Set (std), Piston Ring Set (1st O/s) are included in the Dt400 1978 Usa Crankshaft - Piston parts fiche.
With two applications this Washer 275116850000 is the most specified part.