1960 GMC Burb 305 - Oil Pump

[KIC]

So I had to pull my engine due to a bad freeze plug and decided to follow the normal " While you are there.." routine. swapping back to the original 3-on-a tree tranny, which means new clutch, throwout bearing etc.

Any way I decided to pull the pan to take out some dents in the bottom and ...since I was already there..why not replace the oil pump.

Called several places. I have 3 different parts numbers. I need to order.

Does anybody have the correct part number ?

Two numbers come back to the same style/oil pump the M55, but that seems to be the pump for a V-8

The third is totally different.

I will be pulling the pan tomorrow to actually get eyes on what's in there, but just wondering if anybody knows the correct part number or has a photo of what is in there.