There should not be any water coming from the cleveland intake. If you have water, then it is coming from either the head gasket, or the adapter/intake gasket. There is no water to the cleveland intake. That is the purpose of using the adapter/cleveland intake, easy removal without draining the water to access the lifter galley. Upon reading your post again, yes, you could use a sealant if you apply it evenly. Joe-JDC