On the 2 bolt main 427 in that link...I really don't know much more than the info that's posted. It was a guy on the net54 forums find. And he posted those pics for the nay sayers...and there were plenty of those. He was asking $1500 for the block i think. You can clearly see the shaved sideoiler passage on the side of the block which was common to some marine 427 blocks to clear the motor mounts. Pretty cool find I'd say. I bet he got it CHEAP!! So it goes to show these things are out there.