Tim,
I'm sorry I can't point you at a crankshaft. I though it worthwhile to share that there are at least two versions of the 427 crank. They're easy to spot. The early version has steel plugs in the crank throws with snaprings holding them in place. The later version has screw-in plugs.
My crank was the early version and I had no troubles with it, but, given a choice, I would opt for the later version for peace of mind if nothing else.
I'm certain that other members of the club will have possible cranks and/or sources for you.
Good luck
Al