I have a crack along the lower left side of my 216 block. In previous threads, different ways of fixing it have been discussed. Deciding to go the easy way first, I tried JB Weld with no success. The crack just opened up right through the material. Then I bought a product from Eastwood called High Temp Epoxy (#31177). It is an aluminum-filled resin which comes with screen material to use as reinforcement. Have brought the engine up to operating temp a couple of times since with not a drop of water leaking out.