Priming the oil

I don't recommend packing the oil pump "full". Just enough to seal the rotors, so the pump can pull a vacuum. I have seen a fully packed pump not be able to "push" the vasoline through the pump. Drove me nuts as to why I couldn't get pressure. Actually what I do is put oil in a container that can be pressurized (I use a old freon tank) put oil in the tank, connect the tank to the oil pressure gauge port on the pump. Pressurize the tank, and spin the engine on the starter, with the spark plugs out.
Or if I'm lazy (which happens more and more) Just spin the engine with the starter, and hit the ignition.