If you are staying with a 383 displacement, I dont think you have to worry about needing a bigger head. A set of SRs with a std port window or Edelbrocks, or any MP stuff are already way too much port for your use. The best power will come from the smallest (by volume) port you can get, that moves the air fast (cfms). Another issue with 383s is the small bore size. They shroud valves a lot, and very easily. My advice would be to reuse a factory head. The use of a closed chamber design is preferred if possible, because it allows you to use the energy of a tight quench distance to help the mixture and add detonation resisitance. The airflow in a stock set of typical 452/906/915 intake ports is between 220 and 240 cfms depending on the head and bench, with a decently done performance valve job. That's enough in stock form to make 440-480hp on pump fuel. So, disregarding the "new stuff vs re-using old stuff" debates, I would go something like this: Locate a set of virgin 915 heads. I would install hardened exh seats, new guides, cut the spring seats and guide tops for positive seals, and do a performance 5 angle valve job, fitting 2.14 intakes and 1.74 exh valves. The 2.14s are to get a better seat, without having to replace the intake seats to reuse 2.08 valves. Part of a 5 angle job os an unshrouding cut in the chamber, the other angle is a bowl hogging cut in the port. Those two actions are equal to the majority if "stage 1" port jobs, and are part of the performance valve job anyway. With all new parts and the basic milling and cleaning/magging, you'd be looking at about $1200 in my area. And have a set of well matched performance heads that are ready to run another 80K miles. You can always spend to get more bling, but you dont have to. I know a couple 383s that run 12.0s in B bodys with heads just like this on pump gas. You could duplicate the work on a cheaper-to-buy set of 516s too. But there are sometimes issues with core shift in those castings that may make adding unleaded seats difficult on some heads. But they would save you a couple hundred off the top.
