The strength of nodular/malleable/ductile iron aproaches the strength of low carbon(mild) steel. But, steel has better fatigue properties. A properly made forging is potentially tougher than a casting, but an improperly made forging can be considerably worse than a good casting.
just adding my .02c cast iron will never be as consisant as a forging nodular or not it just doesnt have the shock loading capabilities an example nodular crank is only rated for 500hp ish forged 800-1200hp pound for pound if you want a cast axle go for it you with probably be fine odds are in your favor
The Jalopy Journal
