You need to check and see if your
oil pump is working before you do anything else!
Remove the distributor and you'll see deep down in the distributor hole a hexagonal shaft. (Mmm, if it's NOT there you forgot something on your
oil pump replacement). Procure an
oil pump primer shaft from a friend or the local auto parts place, put it on your drill and spin that oil pump shaft (verify direction, but I believe it is counterclockwise). Your oil pressure should rise with this priming. If not, you'll need to start all over with your oil pump replacement.
Also, careful with the oil line that goes into your cockpit to the guage---if that is loose at the gauge you'll have oil under your dash with all of that live wiring and may have a fire on your hands. Actually, I'd feel around under the dash under the oil pressure gauge first, to make sure there was no leak and THEN pull the distributor and prime the oil pump.
Cheers,
DD