Anybody have a link that breaks down Saginaw PS gear box casting and or part numbers?

I planned on working on the clutch linkage for the 57 today and got sidetracked figuring out the power steering

Anyway I found a steering gear out in the shed that just might work. The problem is I've got no idea what I pulled it off of. I found the casting number and part number but so far have had no luck finding a site to break them out.

If everything goes well and I can make the box work I only want to do it once (the gear will still have to be installed thru the passenger compartment). That being the case If I can make it work, I'd like to put a rebuilt gear in it.......I just need to know what to order



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