Sierra's 18-1903 manifold is made for small block v8 (305-350 CID) engines from 1979 to 1989. Designed to be mounted on the port side. Sierra 18-1921 manifold elbow, 18-2949 exhaust manifold gasket, 18-8502 exhaust manifold mounting kit, 18-2902-1 exhaust manifold gasket, and 18-2902-1-9 exhaust manifold gasket are all recommended. (1) Sierra 18-0943-2 exhaust elbow gasket, (1) Sierra 18-2949 exhaust manifold gasket, (1) Sierra 18-7306 hose clamp, and (1) Sierra 18-0550 plug off cap comes standard with the manifold. Mallory 9-40601, glum 51420, Barr OMC-1-912442, Osco 2442, and OMC sterndrive 912442 are all interchangeable. Sierra products meet or exceed the specifications of the original equipment part they replace.
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