Difference between 2 Saginaw PS pumps

Are you looking for someone to hold your hand? Honestly install it. You will then know if it works. Your car, your car show. Make it happen if you want to go. That’s hot rodding. Not all things are plug and play.
No need to be dickish about it. Some bolts go into cooling jacket so will also have to drain back block. Asking if there is a difference and advantage of one over another. Why two versions of Saginaw? Was one replaced because of issues?