RE: What's the different between a pusher and puller props?
Not only must it be a pusher prop, but something else to watch out for is to get it on the right way.
With a regular (tractor) prop, the lettering and/or Logo (Indicated by the red line in the picture) is facing forward - away from the engine
I have seen many people install a pusher prop with the lettering also facing away from the engine. In MOST cases, manufacturers put the lettering facing the FRONT of the plane.