I do all of my sailing on the Great Lakes ( Lake Erie to be exact). While looking at potential boats I have found the selection to be best on the East coast. That would mean, however, that I'd be bring a saltwater boat back for use on freah water. I'm looking at boats fo the 1980 to 1986 vintage. How concern should I be about a saltwater engine? I know saltwater is a bit tuffer on equipment than freshwater, but am I overly concerned about a issue that is not that important?