Oil pressure on 95 Rover 4.0 SE

[lstill]

Hey Guys,just put my 4.0 Rover motor back together ...Filled the new filter with oil but didn't fill the pump with Petro Jelly...Starts right up and runs well but how can I check to be sure that the oil pump is pumping sufficient pressure. I've read that they can cavitate and not pump oil? Any thoughts appreciated....Larry