Tony, Thanks for the reply. Yes, it might be rebuildable, but the crank has significant play in both axial and radial directions. Not just the pulley, but the actual crank. Just before I shut it down, it sounded like there was a big load put on it, and in a couple minutes it overheated. It is likely to need more than a freshen-up. The old Allis is a wonderful little tractor, but there are noises in the tranny, could use a radiator, and other stuff that just doesn't make it a good fit money wise for sinking $ 2000 into the engine. Also, parts are difficult to find for this France made Allis tractor. Now a $500 running engine would change my direction. Haven't found one of those yet. I've learned my lesson to attend to an engine when it needs a re fresh rather than after it gets too sloppy and something gives.
I'm located in S. Jersey, my farm is on Marlyand's Eastern Shore.