Help w power steering pump

[rico7769]

Hello Fellow truck junkies! I have a problem that has been haunting me since I bought my 67 GMC last year. Power steering!!!! I am running a sb350 w th400 tranny from a 77chevy P/U. The hoses and gearbox holes are not compatible with each other. So, I finally broke down and had a custom hose made a couple of weeks back. I bought a new rebuilt P/S pump that is compatible w/ our motor and mounted and installed w/ a new belt. Upon startup, I noticed a hole in the rear of the pump to the right of the pressure hose inlet that was dripping fluid very heavily. I've been researching online and found that there should be a post/bolt that goes in it. I guess the person that rebuilt it failed quality control. ha ha...not for me though. My question is this: Does anyone know the reason for the hole? My best guess from pics online is that it shouldn't be there and most pics show the stud. Does anyone know the correct dimensions and size for the stud that should go in that hole? It is the only thing really holding up my dream of power steering.
Any info would be appreciated.