Priming the oil pump
On a rebuilt engine or if just changing the oil pump, you can do considerable damage to the engine if you try to start it without oil pressure. It takes quite a few turns to purge the air out of the system on a new pump.
Begin by removing the distributor to gain access to the oil pump drive. Be sure to set the engine at Top dead Center and carefully mark the rotor position before you do.
Look down int he hole and you will see a slotted shaft. That is the top of the piump that you need to spin. A large flat screwdriver will work.
However what I use is an old distributor. The distributor fits the shaft and the hole perfectly to avoid any damage and it is easy to chuck a drill onto the shaft where the rotor button normally sits.
You will have to remove the drive gear on the old distributor. This task is accomplished by knocking out the roll pin that holds the gear to the shaft and tapping the shaft loose from the gear. You can leave the sensor in place, just remove the rotor button.
Drop the gearless distributor in the hole. No need to bolt it down. Chuck a 3/8 drill to the rotor shaft and spin clockwise.
I put a pressure gauge in place of the sending unit so I can monitor the oil pressure during the operation. The drill will spin easily until it picks up oil. Then it will suddenly get harder to turn. Hang on to the drill.
Be careful not to spin the pump too fast with no oil in it. You can pick up speed once you feel resistance. Continue to pump oil until you see pressure on teh gauge. Spin it a little longer to prelube the bearings.
Stop and watch the gauge go back to zero. Then start slowly again to make sure the pump is fully primed. Oil pressure should pick up quickly one the air is out.