4 Cylinder Exhaust Manifold to Head Gasket | Sierra 18-29304 Cylinder Exhaust Manifold to Head Gasket Sierra 18 2930 Gasket seals exhaust manifold to cylinder head on various Volvo Penta AQ model marine engines. Exhaust manifold gasket Fits Volvo Penta AQ 120B, 125A, 125B, 131A, 131B, 131C, 131D, 140A, 145A, 151A, 151B, 151C model engines One piece gasket is different from the OEM part but will directly replace original gaskets Replaces Volvo Penta 1266796, 1378879