I *think* the a/c pumps have less blades. They also have a smaller pulley, due to the a/c pulley being linked, so they should move a similar amount of water. Rob> >My car has A/C, but somebody (probably me!) put the non-A/C pump in many >years ago. With the new, correct pump in, I pulled a 4000-pound trailer >over a 2000-foot pass at 86 degrees with the A/C on and never went past the >high end of the normal range on the temperature gauge. A marked >improvement over the past! > >If you're having difficulties keeping your engine cool, this might be worth >a try. > >Ken Miller >Portland, Oregon >61 and 67 Converts (and a 64 New Yorker Salon) > > >