It's the IH waterpump. International, napa, etc carry them. This kit is nice because it has all the other stuff you need. Bolts, t-stat housing and lower hose. I am assuming the boss is ground off already also. You can run a standard stat with these also.
I heavily flushed mine with water and put an IH pump on. Switched to ELC coolant and a little bit hotter stat. When I change the filter I open the old one up. They are getting progressively cleaner so I hope this pump really hangs in there. Fits and looks great... almost like it was designed for it