BARR MC-1-77234 Port side manifold Replacement for Mercruiser Manifold for GM (Chevy) small block LOG style (End Riser). Note this manifold has the square riser mounting flange pattern (2-13/16" x 3-1/16" bolt centers). Supplied with: manifold to head gasket, (2) end cap gaskets, RWC riser gasket, and manifold to head bolts. If needed, order riser mounting and end cap hardware separately. Made in USA, 3-year limited warranty.