All of the Saginaw "Canned Ham" looking pumps use the same outlet threads behind the large 1" fitting. Use a 1" wrench or a good crescent wrench to swap out not only the fittings, but also the pressure relief spring and valves from your old pump into the new one - or else you may well get who-know-what for steering pressure / flow / feel.
(I did a similar serpentine swap as you, and the '92 PS pump's valve doesn't give nearly as much assist as I'd like.
Check out this website, you want to swap parts A, B, and C.
http://www.gmtruckcentral.com/articl...rsteeringmods/