Replacement Water Pump Kit - This water pump is an engine-powered bi-directional pump that circulates seawater to maintain the right engine temperatures. Replacing the water pump is a safety measure that needs to be done regularly every 75,000-100,000 miles to prevent engine damage before it fails completely. Compatible Replacement with the following - 1963-2014 Mercruiser | 1973 later Volvo Penta | 1968-98 OMC | 4.3L, 5.0L, 5.7L V6/V8 Engines | Chrysler, Indmar, and Pleasurecraft small block cooling systems - 140-200 Hp | V6, 155-205 Hp | V8, 230-260 Hp small block GM MIE engines. This water pump is applicable to steel and composite timing chain covers and all small block V8 engines. It can easily be located above the lower gear case assembly. Replaces Part# Mercruiser 8M0113734, 8503991, 850399, 17437, 850399002, 878341, 811841, 60658, FI1101292, 54793, 52226, FI1101208, FI1100742, 37951, 35341, 18-3599-2, MW02, WP1500, MC-2-17437, 20318, 15201, S551045, 9-42606, WP453ML, RA057018. This kit includes a new black solid steel water pump, stainless shaft, pulley and steel backing plate which provides maximum corrosion resistance and durability. OEM Fit, Quality, Finish - While this is not a genuine OEM part. It is a direct replacement and comes complete with new gaskets 18-0891, water pump with brass tubes and stainless impeller cover for a complete proper installation and performance. If your boat shows low water pressure or stops circulating water which can cause overheated engines then your water pump may need replacing.