I would replace that fitting right away. You can get som salt away stuff from the marina and should use it when you flush your motor. I have a lawn firtilizer deal that goes inline with the garden hose. I fill it with that salt away stuff when I flush the motor after a day in the salt. From not seeing your boat I would think that you got a pretty good deal for less than ten grand. Price a twin turbo set-up some time. They are not cheep! You could not build a good to go turbo motor with all new parts for ten grand.