Mercruiser GM Small Block Exhaust Manifold | Barr Marine MC-1-47737Mercruiser GM Small Block Exhaust Manifold Barr Marine MC 1 47737 Port side log style manifold fits Mercruiser 225, 250, 255, 270, & 280 model marine engines. Barr Mercruiser exhaust manifold Direct replacement Mercruiser GM V8 small block log style exhaust manifold Port side For Mercruiser 225, 250, 255, 270 and 280 models Includes gaskets and mounting hardware 3 3 8 in. x 1 3 4 in. exhaust elbow port size Heavy duty cast iron Painted black Replaces