Find someone to show you pics of a broken block. I haven't seen even one yet, or even heard of one. The only issue seems to be oiling the crank at very high RPM. Put a decent rotating kit in it and I don't think it is gonna break any thing, especially if you put more cubes in it to bring the RPM down.

They can and do run very good, they took the top two spots in the engine masters challenge, the stock block is trusted by the factory to handle 800 hp in the hellcat (707HP Net+80HP to drive the blower+a little room for safety). There are plenty of bad to the bone gen III running awesome times in super stock, even stock heavy turds running very fast.

Anyone saying they don't do well is a cheby or ferd guy scared to admit the truth.