For what it's worth, I've got the same problem on my 44 1 1/2 ton with a low pressure 235. Crack on the left side, water jacket only. Mine's BEEN JB-Welded, or something. It still drips quite a bit of coolant, I top it off every other outing or so.
Long term, I figure I'm replacing the engine, or at least the block. I've got a friend who heard about some wierd stuff you put in with water or something after warming it up . . . can't remember the details, but it sounded roughly like the stuff you would use to plug a whole in a radiator.
Makes me nervous - what if it plugs up a critical cooling passage? I'd like to find out if it can be truely welded, but I don't know enough about it.
Still looking and learning . . .
Good luck!
-Michael
