I'm dealing with the same issue on my 360/410 right now. Poured in five quarts and it won't pressurize (turning clockwise)

Removed the oil filter and adapter and found it bone dry.

Stuck a rod down the sending unit hole and hit the plug right where it's supposed to be.

I double checked to make sure all galley plugs were installed when I got the block back, so I'm certain that's not the problem.

Reusing this pump from my 340. Looked brand new and worked fine in the old motor.

Running a Kevko pan and pickup. Pick-up depth is right where is supposed to be.

Looking like I need to drop the pan to see what's going on.