Lots of good info here on impeller changes. Also, see the Don Casey Reference Library on the Boat US website. The only caution I would add is that I would be very careful using two screwdrivers to pry out an old impeller. It is very easy to gouge the relatively soft water pump rim which must mate tightly with the water pump cover. I think you would be better off trying to pull out the old impeller with a needle nose, or similar pliers by grasping it by the base of a vane and wiggling it out. If you do use two screwdrivers, put a protective ring of masking or similar tape around the shaft of the screwdrivers where they will contact the edge of the pump housing as you lever out the old impeller. If you nick or gouge the pump housing, you are probably going to be buying a new water pump....
