Parts such as the Camshaft/valve: Spg,in Valve Out., Arm Rocker In B, Spg Ex Valve Oute, Nut, Tappet Adjg. are included in the Xl600v Transalp 1987 (h) Spain Camshaft/valve parts fiche.
In this schematic the "Cotter,valve" is used most often.
The Nut, Tappet Adjg. is the cheapest item from this partsfiche.