Any thoughts on cast cranks vs forged steel or 4340? I'm building a 383 at 400-500HP and I want to make sure I get the right piece.

 

you plan on using any power adders? turbo,nitrous,supercharger?

 

You probably want a basic forged piece.
The $900 lunati sledgehammers are probably overkill for you. Something like a $400 forged eagle piece of something would be good.

For that kind of power, you'll need to spool it up to a high RPM, and that's what causes the stress. Cast iron would be quite dicey. Cast steel or an entry level forged one would be ok. 4340 is usually in a forged state.

 

Generally cast cranks are better for street since cast has better wear characteristics but are more brittle. Forged steel is stronger but can wear faster. 4340 would be best for longevity and strength anything in between would be a waste IMO.