90 cadillac water in oil

can the inner water pump gasket be a source for and internal water into the oil type of leak, it is visibally leaking externally now?

Not in the 4.5/4.9.

Ok, could any part of changing the timing (belt?, chain?) be a potential cause of water now leaking into the oil?? the oil became milky after an unknown mechanic (not professional) changed the timing belt/chain.