Hey guys. Have a 74 cheetah with a 454 in it. Has glenwood log manifolds and water risers through the transom. Yesterday I checked the oil level and noticed it was milky. First thing I thought he's gaskets or worse, block issue... So as I was check things and draining the oil I was walking back to the driveway when I noticed one of my exhaust flapper was completely gone! Could this be a possible reason for milky oil!? Thank you.