So it was all fresh and new, with a new crank, ready to go back in. Which it did. Then it ran for almost 5 seconds and stopped. Then it wouldn't turn over.
In the case of "I've never seen this before", the forged 383 crank was not drilled for a pilot bushing. Go figure. So after pulling the engine, replacing the thrust bearings I crushed with the input shaft, cutting the end off the input shaft of a $2500 transmission, and putting it back together, it still wouldn't turn over.

So back out it came. More off the input shaft. More measuring. Back together. No turn over. So we finally figured out the two year old Year One positive battery cable was junk. Replaced, fired it up, and finally I was able to drive it.