Doug,
Don't forget your local Ford dealer. Over the years I have found that the over the counter replacement parts for water pumps, starters, and other parts are of a better quality than my local parts store. They fit better and last longer.
And they are not that more expensive and sometimes very close to the same price. I had a 65 Falcon Ranchero with a 289 with the alluminum water pump. My Ford dealer was the best pump I ever got. I went through a bunch of rebuilt pumps that wore out in no time. The Ford one was new and a bit more expensive but way better quality and lasted for years until I sold it. Still is on the car today.
Might be a thought.
Rob