It's not a question of power, it's just time. A very slight looseness of bearings that would never hurt a cast crank will shatter a steel one. In the case of the 318 truck engine, the oil pressure dropped, and before I could react, the crank broke in two places and wiped out everything but the exhaust manifolds! (It was flat out at the time.) Block, heads, even the 340 hirise intake, all smashed to hell and gone.