I pulled the port riser on the starboard engine and was able to feel around the oil lines coming out of the adapter, into the block and around the oil cooler. They seemed very dry and tight. I also felt around the oil pressure sensor (for the PCM) that is next to the oil filter pad and I was able to pick up some oil on my fingers there. The fitting going into the block was very tight. I put a 1 inch socket on the sensor unit and I could turn that pretty easy. So I tightened that down and tried tightening down all the hose fittings and adapter bolt, but they were all snug, couldn't move them. I'm going to put the riser back on.. I'm not sure what else to check. I could see the drain hose with a mirror and it looks dry also.

I don't know what the oil pressure sensor looks like on a 496. But on my Mustang race car, the factory oil pressure sensor can leak through the sensor housing itself where the wires come out. Same thing was happening with my transmission's reverse light switch. Spray a little brake cleaner on the sensor, just to get any gunk off. Then check it out again after you run it next.

It ended up being the 45 degree fitting the oil pressure sensor for the PCM. It was cracked.

Same thing I had.