Last one to post in this thread wins!

Ahoey said
As far as I ever knew there was only two styles of water pump for a Sbm
The standard one, and the AC pump with the smaller impeller. Take the time and use a straight edge to check the alignment of your pulleys. Saves big on belt wear. Takes a few minutes and some washers adding or removing.

Early ones are different to facilitate the mounting of the power steering pump. Not a great picture of it, but if you blow it up you can see the mounting bracket on the top left of the water pump.