Main cap girdles re-discussed
I do tend to agree that the limits of a well set up factory block seems to be overstated. The guys that say the block has a power limit of "X" don't reference any specific evidence. The only broken blocks I've seen so far are due to other things failing. Ex. Broken pistons (detonation/rings butting), snapped or bent connecting rods, broken engine mounts etc.
I'm not saying it's never happened, and I do trust the guys here that have been running hard for decades, they know what they're talking about. But I would like to see what the documented limits of a well set up stock block are. A block that didn't have the carnage of other broken parts cause the block failure.