I'm here to tell you that this process DOES work ! I have a customer motor that I recently completed that had a similar problem. 413 Cross Ram Mopar. Numbers matching for a 1 of 75 '61 300G Convertible. Crack on the outside of the block. We "stiched" it and not only is there no more problem, but you'd be hard pressed to see the work. My first coat of paint on the engine, and you couldn't see it anymore. GOOD LUCK !!!!
