oil pressure and priming

I have another post related to this but I need another point of view. I have my sbc 400 out of the car w/ the intake and heads off. When priming the engine should the amount of oil that comes out the oil pressure sending unit port behind the distributor 'If you had it unplugged" be the same as if you had a oil gallery plug unplugged?That's what I'm trying to nail down here.
I would think that it should come out of the rear oil gallery hole like it does the oil pressure sending unit hole. But it doesn't it just kind of seeps. The same with the oil gallery hole that's inside the block right inside where you prime the oil pump on the rear side of the block. I'm wondering if I have some sort of restriction in the oil gallery.

It's pressure.
The oil comming from the oil galley plug (which is roughly 3/8" hole) will be less.

the hole for the pressure unit is about 1/8".

Just like a garden hose, put your finger over the end and the pressure goes up.

Plug everything up, get a pressure guage, screw it in the hole for the pressure unit, use a priming tool, or an old dizzy, and a drill and spin it!
You may need to rotate the crank a bit to make sure everyhole is open.

Yeah thats pretty much what I'v been doing. It just barely comes out of that rear left gallery hole.

Don't use the galley hole, use the standard hole on top of the block near the dizzy.
Put in a guage and then check it.