63 401 water pump ac non ac difference

What is the difference between a ac and non Ac water pump on a 63 401/425?

 

3 blade impeller as opposed to a 5 blade impeller for an A/C car.

 

Thanks! I couldn’t see why there would be much difference between them. Now I know!

 

ALSO the 5 blade impeller has a larger bearing on the end so "should" last longer. Some say that if you install a 5 blade where a 3 blade should be the engine will overheat. In my experience I don't believe this is true. I know non A/C cars because of the pulleys & design that the water pump spins at .9 engine speed whereas the A?C version spins at 1.1 times engine speed. It ALL has to do with the pulleys.

Tom T.