When you get to the 650-700HP range they will fail. I never blew one up, but when you take them apart to freshen, they have cracks and problems. No 2 main if you use stock caps will always be the one to crack and break. I had one filled with concrete and the cylinders started to fail and it pushed so hard on the concrete it cracked between the freeze plugs, never leaked water and never blew up, but it was junk. Last stock block I did had a main girdle, and filled block with side bolt steel main caps, ran it 4 years, but when I took it apart to freshen, it was cracked along the oil hole that fed the main to the cam bearing on number two main.