Oil pressure, 400 4bbl, 74 Charger

[Bob]

Ok, this is how it went. 2 weeks ago went out for a quick but gentle spin around the block. Heard a light tapping noise from the lifters and noticed no oil pressure. This is what I did:
Checked the oil, good.
Check oil pump dive, good.
Removed oil pump, reinstalled the filter, primed the pump, held my thumb over the outlet hole, rotated the pump drive by hand for approx 2 minutes, removed my thumb and a little poof of oil came out.
The oil pressure gage only read at the first mark or sometimes a little below since I owned it. About 4 months ago I did replace the cam but everthing was fine. I very seldom hammer the car so I'm hoping it's just a weak pump.
I ordered a high volume pump.
Any suggestions or similar situations out there?
Bob

[Nacho-RT74]

Worn oil pump maybe ?

[Chryco Psycho]

replace the Pump with a Melling High Pressure  pump , often the bypass valve will get stuck & drop the pressure way down
you do not need a High Volume pump 

[Bob]

Yes, that's what I ordered.
Thanks

[Bob]

Ok, I picked up the pump last night. I don't have a special tool for priming the enginge before I fire it up. What can I do to remedy this?
Update: I got the M-63HP instead of the M-63HV.
I should have gotten the high volume instead of the high pressure. Should I return and switch?

[Nacho-RT74]

IMHO High Volume better, since you can change on that same pump, the spring to convert it on HV/HP.

[Bob]

Oooops. It is what Chryco said to get. Guess I'll go ahead and swap. Been a long night.
The pump, 5 quarts of Penzoil & filter, $51.99
Autozone is the way to go.

[Bob]

Pump installed, new distributor, changed the oil and filter, set the timning and "on the road again".