This item has been discontinued by the manufacturer and is no longer available.Sierra 18-1978 ElbowSierra elbow for use on V-8 inboard applications only.Use With: 18-1950-1: Manifold; 18-1951-1: Manifold; 18-1954-1: Manifold; 18-1955-1: Manifold; 18-1956-1: Manifold; 18-1958-1: Manifold; 18-1960-1: Manifold; 18-1962-1: Manifold; 18-2833: Exhaust Elbow Gasket; 18-4362: Exhaust Elbow Mounting Package; 18-1906: Manifold Spacer; 18-4008: Block Off Plate; 18-8514: Exhaust Elbow Mounting Kit; 18-8554: Exhaust Elbow Mounting Kit; Interchangeable with: Barr; MC-20-76771; GLM; 51190; Mallory; 9-40556; Mercruiser Stern Drive; 76771A3; 76771A2; 60427A2; 53779A2; 53779A1; Osco; 6771;