Stock Magnum Intermediate Shaft w/Melling M72 Oil Pump?

Attached is a photo of the intermediate shaft alongside the priming tool marked where it bottoms out.

Oil pan is on but you guys have confirmed what I was thinking. I'm gonna have to pull the pan and see what is happening at the pump. Was hoping maybe someone had run into this and I could avoid that but sounds like something is not right.

I have oil in it and used the priming shaft to prime it and confirm I had oil to the valve train. I did so I assumed all was good.

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Was that a brand new priming shaft? By the little wear marks, it looks like only the very tip of it engaged the oil pump. I would venture a guess that something is inside that pump, keeping it from going in.