Now that I have the engine out I can clearly see it has a cracked block. My neighbor says it can be welded and work fine. But here is my concern. The reason I started this project is because pressure was building up in the cooling system without getting warm. It looked like a textbook blown head gasket. After I got the heads off the gaskets looked fine. I would think even with a cracked block coolant would simply leak out, which it was. How was the exhaust gas getting to the cooling system? Seems it would be a problem with the head but could it be the crack in the block? Any suggestions would be greatly appreciated.