Power Steering pumps ?'s

[ck5566]

I am going from a Non Power Steering Truck and putting on Power Steering now. I am going to probably re build one of my two Prw. Strg Pumps that I just recently acquired and I would like to know how to tell if one of them is a OEM pump or aftermarket? Do the pumps have any numbers anywhere on them or any identifying marks? My two pumps are still dirty/greasy. I also have seen that there is a Eaton pump & a Saginaw pump, how do you tell which one is which? Pictures would be good. When I clean them up and paint them I will post some Pictures. Thanks in advance

[joeydurango]

I could be mistaken, but I believe the original pumps all were the "chimney" style, where the filler neck was a separate piece from the main reservoir. The newer pumps are more square in shape and don't always fit - NAPA sold me one that was a claimed direct replacement but because the integrated filler neck was larger, it contacted the mounting bracket on my K10 and didn't work. I had to go get my 44-year-old pump back to make it work. Sorry, no photos...