FWIW, I would likely pay $2400/2500 for a decent copy of the early 400 "230" block if it did not require significant additional machine work. Cross bolting or 4.5 bore not even required, though it should have good caps and be 4.44 capable. And I did buy one of the last pre-World megablocks.

With the exception of a one off piece, I don't think there has ever been an aftermarket low deck iron block.