Thanks for the replies. I did put some of that underwater epoxy stuff over the crack and it slowed the leak down to a slow drip. Should get me through this season. I'll keep an eye on the oil for signs of water contamination. I see no oil in the water, so I figure that's a good sign.
simpsoned, Do you happen to know what your friend paid for that and what the outcome was (ie did the weld hold up over time). Cast iron is a pain to weld correctly. I had been thinking of trying to find a used one to swap in this winter.