That one's a pretty classic freeze crack. Unless you have a specific reason for wanting to reuse that block, I'd suggest finding one in better shape. 235's aren't particularly scarce or valuable- - - -there should be plenty of good condition replacement blocks available. I've got several of them stored away if you're interested. Drop me a PM if you like.
There's a company called "Diesel Cast Welding" that does excellent quality crack repair, but they're pretty pricey. The machine shop where I used to work used them extensively for repair of high-dollar Cummins and Cat blocks and heads. I'm sure you could get that crack repaired by someone with their capability, but it would cost several times what a replacement block in better condition would run.
Jerry
