Cracked C59A block... any repair ideas?

[supereal]

At our shop we repair block cracks that don't involve the water jacket, such as the area in the valve pocket, by drilling and tapping a hole, and inserting a threaded plug, followed by some good sealer. If the crack is into the water jacket, or at the bottom of the bore, it is unlikely a repair will be successful. When we rebuild a flathead, we install hardened seats. This provides the best way to prevent future problems.