Just a couple of thoughts. First if it's the GMB that has the metal impeller, Carparts.com has it for $53.46, shipping to me would be $7.31, but your milage may vary.
Also in the June issue of Car & Driver there's an article about which anti-freeze to use and there was one quick line that said that Ford's used it for a brief while but then stopped. They basically don't recommend using the Orange antifreeze (Dex-Cool) unless the car came with it. It may eat older style radiators with lead solder.
