When it's cold, around 900 - 1000 RPM. When it's warmed up, around 600 - 800 RPM. And Scotty is dead on about the location of the oil pressure sending unit. They're inexpensive, and removing them is a matter of unplugging the harness, and unscrewing the sending unit out. It's just a bit of a pain due to the lack of adequate working room.

BTW, how'd this end up in the 2.3 Quad4 section?