Casting # will tell you which rotation it has. Get the casting # and google it. Or you remove the pump, take the back cover off and look at the direction the vanes go. As the housings are the same and only the impeller design is different you wont be able tell from the outside, only with the casting #. On some aftermarket pumps there is a little arrow cast into the pump casing to show the direction of rotation. I think not on stock pumps.