I've begun to work on some of the items on my maintenance list for the off season. Today I pulled the port sea water pump to replace the impellor. When I inspected the brass housing after removing the impellor I noticed curricular score marks on both the housing and end cap. The scoring is deep enough to be felt with my fingers. I wasn't having any engine cooling problems last summer but, now that I know the pump housing is worn, I'm not comfortable just installing a new impellor and reusing the pump. It's gotta go! My question is: what would those of you who have been in this situation recommend? Should I go with a new OEM pump from Merc, the replacement from Sierra, or a stainless steel pump from Hardin Marine? I read on a previous post that someone got the pumps from Hardin Marine and experienced early bearing failure. The OEM pump has lasted 6 years so I would likely get that much or more from a new OEM unit. Are the stainless steel pumps as reliable as the original units? Thanks in advance to all who reply.