Rons Porting in MO
I have dealt with Rons in the St. Louis area. Well known for his small block hand port work for over 30 years. I had him do porting and it was excellent quality. You get what you pay for from him. He has CNC equipment that is up to date and knows what works.
Sorry, I don't know about the specific head you are working with, but Rons is a good place to start.
He is in ST. Charles, MO.