crankshaft question

I just bought a '71 318 complete from carb to oil pan from a guy that had it sitting on the floor of his garage. As far as I can tell the thing has not been apart since it left the factory, and it has the crank drilled with a pilot bushing installed to boot. It had to have come out of an automatic car, since the bushing looks new with no wear on it, and the hole was packed with gunk. Weird.