Replace your rusty, cracked or just poor performing Chevrolet 4 Cylinder Exhaust Marine Manifold on your 153 & 181 C.I.D. Chevrolet Engine with a Direct Replacement Mercruiser Chevrolet 4 Cylinder Exhaust Manifold, MC-1-0120. Barr exhaust manifolds are built for the marine environment and are easy to install. Manifolds by Barr are covered by a manufacturer's 3-year warranty. We recommend that you purchase replacement manifolds in pairs and to also replace the risers and elbows at the same time.