When I said "sea" water, I meant any type of river or lake water too. If it has not been in a boat with a closed cooling sytem with antifreeze, I would be VERY leary of it. I see a mess of marine engines and most of them are pretty eaten up after ten years or so. If the freeze plugs are out of it, it is pretty easy to look in the block to see how corroded the insides of the cylinder walls are. Also look real closely at the bolt holes and around all of the water passages in the deck.