Seals between the exhaust elbow & exhaust manifold on Mercruiser 165, 470, and 3.7L marine engines with cast iron exhaust manifold. Mercruiser 224 CID Exhaust Elbow Gasket | Sierra 18-0113-1 Sierra exhaust elbow gasket For Mercruiser 165, 170, 180, 190, 3.7, 470, and 488 engines used from 1983-1989 with cast iron manifold 224 cu. in. Replaces Mercury 27-97542, 27-856705 Replaces Mallory 9-61411