You might want to search the files. Most guys swear by the metal impellar water pump, although I've heard that Ford's current version of the pump has an improved impeller made of a different synthetic material. As far as installation problems, I haven't seen any comments about that.
Myself, since I have my service done at a Ford dealer (and believe it or not guys, I'm pretty happy with them!!), I'll have to settle for the new Ford version of the pump.
