Hi. I have a 1994 150 hp Johnson Fast Strike that I purchased new in 1994 with my boat. I have never replaced the water pump and (after reading the many posts about changing it on here) probably will this spring. I have a couple of questions. First, can I get by with just an impeller change? If so, what is the part number of the impeller? If I need to install a complete water pump kit, what part number kit would I need? Thanks very much for the help. Are the Sierra kits I see on here ok or should I stick with the original OMC parts?