Parts such as the Turn Signals: Screw,6x14, Bulb.12v 23/8w, Collar, Screw,tapping,4x25 are included in the En450a3 454ltd 1987 Usa California Canada Turn Signals parts fiche.
With eight applications this Screw,tapping,4x25 is the most specified part.
The most expensive part in this assembly is the Lamp-assy-signal,rr.