[hewittca]

Thanks for the suggestions everyone. I have heard that it is difficult to weld a crack like this, so I probably won't try that.

I bought some of those tablets mentioned, but have not dropped them in yet. I had someone else mention that they could gum up spark plugs if there is an internal leak. My thinking is if that's true, then at least I'll know it's leaking internally as well and I should really start looking for a new block.

If I drop the tabs in, I'll probably also slap some sort of epoxy on the outside as well. I'll update once I try a few things and let you all know what happens!