bad news about block

Other than finding the deepest pit and trying to measure it's depth...I think experience is the only way to tell if a block will clean up or not. If this guy wasn't sure he should have tried to warn you or taken a different approach with the block such as boring the worst cylinder first. Whatever, your questionable block plus his inability to recognize junk equals a discounted price on the block labor. After all they were unable to return a product for your money.