Cast vs. Forged Crank?

The Ford 351C crankshafts were routinely spun over 9500 in stock eliminator and NASCAR racing and all they ever were was nodular iron.
I ran 351-c's in my dirt cars... never a crank problem but I kept the rev's under 7K...except the one night when one of my pit guys hot lapped the car and did it in first gear! Tossed a rod but the crank was OK... that old Ford sounded like an Indy car down the straights... we figured it was at about 9,500!