Alpha I gen I waterpump part number?

[SCORPIO]

OK, I feel stupid, I can't find the part number of the kit I ordered the last time. Does anybody know which part number for a 1989 Alpha I Gen I complete waterpump assembly?
Why is it so difficult to list applications in the parts catalogs? I see numerous references to "replaces Merc # so and so" but never see "fits Merc Alpha I 1976-1991" or something like that. There seem to have been a lot of different pumps over the years and I have no idea what the differences are.
Rant over.

 

[SCORPIO]

I must be tired, I looked up the receipt for the last pump I bought and I found Sierra 183320 so I think I answered my own question, but is that what others are using, brand not withstanding?