I can't seem to locate the oil filter on my 1988 4.3L OMC Cobra V6 marine engine...Is there one, and if so where do I look for it, and what kind does it take to replace it? I thought I had found it, but after standing on my head to remove it, found I had removed the fuel filter and water separator. I'm at wits end trying to locate the OIL filter...if there is one. Thanks...Ron