340 identification

well that answered my question, never thought I’d get my hands on a 340 so I don’t know all the specifics but hey I guess the big lettering on the balancer saying,”use with cast crankshaft only” might be a good clue haha.
Yup, if your balancer has that cast into it, chances are it still has a cast crank and is still externally balanced. You would also need the correct matching flywheel or converter, or, a special flex plate to take the place of the weights on the converter. There used to be some weight kits available so you could add the appropriate ones as needed. I don't know if they're still available or not.