I'm wondering if this crack is the end of the line of just a characteristic of the old sand cast process? I'm picking out a block to reassemble this winter. I noticed it is a "B" casting, though when I look at other bare blocks there doesn't seem to be a difference. "B" castings seem to have run from upper TS30k range to only low TS 42k maybe? After that I see "C" casting codes. Or am I lost?