i have a friend who was a ford racer and ford steel cranks are rare. He used cast cranks without issue but thought that limiting rpm was the key to longevity. i have noticed that some cast cranks have fillets, which is good, but mopar doesn't.
A friends 460 cast crank broke at speed not a pretty sight. Everything, cam, rods, cam journals, the whole center of engine were in small pieces in the oil pan. 69 Mustang running 6.20s all steel, so he was making some heat.
