Wow! 230 cold weather block, casting date two months before they went to the smaller main webbing. Looks like may be a very light sign of cap walk on that one main journal. If your building a 13:1 race engine, it would almost be worth it to sleeve that one in the thinnest cylinders. A BCR main cap and girdle kit would make that the strongest factory production block imaginable, possibly even strong enough for a set of B-1 original heads.
