cracked slant block

About a zillion years ago, I had a cracked block in a 1964 straight-6 Ford Fairlane wagon. With the engine in the car I used a round wire brush on a drill, cleaned off everything around the crack, then mixed up some JB weld and slobbered it all over the crack and surrounding clean block material. It worked like a champ, and never leaked a drop for the several more years I drove it before parting ways.