FWIW, a few things I remember when I was researching heads for a 383 stocker:
The 452 casting has the best low lift numbers.
Milling the intake face lowers the intake volume and makes room to......ahem.....well, customize the port and maintain the NHRA intake volume specification. NHRA states a limit to how far it can be milled. It cannot go into the valve cover bolt holes.
A 45 degree seat on the intake is NOT the angle you want. A 30 degree seat flows better at low lift numbers and may be preferred.
The Edelbrock acceptable head comes with a weight penalty, and has the wrong valve sizes, thus different valves and seats may be required.

Disclaimer: It's been a few years and the rules may have changed, and all this info may be nonsense.

You may be able to purge some better info on Classracer.com