Base transmission for a ‘72-‘74 (maybe later?) B or E body with a big block. Who knows, maybe even C body? I would imagine far fewer than would have been found behind 340 cars, because 340s were an option in B & E bodies until 1973.
I have a 70 and up dedicated three speed big block bellhousing. I think the A230 was it that late, was it not? It does fit the A230 and I believe that transmission has a bolt pattern all its own.