I have a 72 240 I've had since new. My son and I restored it about 15 years ago. I was driving it the other day and the oil pressure gauge went to almost "0". I've checked the gauge by grounding the lead and it worked fine. I've replaced the sender and no readings, or very slight reading. If I take the oil filler cap off and look in, oil is splashing around inside the engine. I changed the oil and filter about 6 weeks ago. The engine runs and sounds fine. Any suggestion on what to look for next? Thanks Don