Mercruiser 3 in. Exhaust Riser | Barr Marine MC-20-76668 Direct replacement 90-degree exhaust elbow fits many Mercruiser I/O's engines with log style exhaust manifolds. Barr Mercruiser stern drive exhaust riser Fits Mercruiser 225, 250, 255, 270, and 280 model marine engines with log style exhaust manifolds For use with 3 in. ID marine exhaust hose Rectangular bolt pattern 2-3/4" x 4- 1/2" bolt centers Includes plugs, gasket, and mounting hardware Heavy duty cast iron Painted black Replaces Barr MC20-76668 Replaces Mercruiser 76668A1, 76668A3, 72964A1, 47877A1, 47877A4