[Hodo]

You maybe jumping to conclusions there. Slow down, what all did you have done to it. It could have been from where you had the heads off and water got into the oil passages that way. Or it could just be a small water leak through one of the gaskets. Could also be when you had the water pump off it could have ran down the front of the engine and got in through the front of the oil pan gasket. (I am reaching here becuase I have NO clue what kind of Z or what you were doing to it.)