700HP 383 Buildup

I think 500 hp is possible with standard heads on a 383.
I'd install 2.14 intake valves and 1.81 exhaust, port a bunch and polish, match the ports to your intake and a good multi-angle valve job.
I put Manley Pro flow stainless steel valves in mine hoping for a little extra flow. I'll have to wait until the cars all done to find out. I built these heads before all the aluminum ones came out, or I would have grabs some of those.
You'll need a big cam too, I've got the 590 lift MP solid in my 383 but I wish I would have gone with a 600+lift roller instead.
I assume your putting this in a A body, just remember you can always lighten the car to get it to go faster.
Good Luck