Can anyone tell me on a stock mercruiser BBC what hose is out from the oil pump, and what line is the return? (or post a picture) There are two fittings next to each other. (X__X) I could obviously take them off and turn the engine over to see what one has oil coming out. I am thinking I might have got the lines reversed going into the filter. If the filter has an anti siphon valve in it, and its reversed wouldn’t that stop the flow? As I remember I also think there is a pressure relief valve also?

Oil from the pump comes out at the off center port on the remote filter adapter. Then back into the moter after going thru the filter and coolers at the center port.
Just remember that oil flows into the filter thru the outer holes--->thru filter elements---> then out of the filter thru the center.