[OMC-Boats] water in oil ?

I was woundeing if some one can tell me how to check if i have a bad manifold or blown headgasket i currently have it apart thinking it was ahead gasket because the moter did get hot before the idiot light came on,i changed the oil out once and it took awhile but came back it didnt seem to miss on any cylanders the original metal gaskets seem to be o.k but whos to say,or what else am i missing here,1969 sportsman 155 .69 sportsman.
Received on Friday, 9 October 2009