After overhauling 1972 Chevy 350 how do you reinstall the distributor?

set #1 piston front right if ur faceing the water pump on tdc then turn the destributer to where you want #one plug wire to be and look at the oil pump drive on the end of the gear then turn the the oil pump shaft bye sticking a long flat head screw driver down the distributer hole so it lines up with the drive slot on destributer gear once you have that where you want it drop the destributer in while turning the rotor slightly to engage the teath on the gear ....if it dosent drop all the way down the oil pump driveisent engaged an will need to be turned ......it may help to mark on the screwdriver handel which way the blade goes