I work in the machine shop where we build performance racing engines. . To get the heads to do what he wants will probably cost him about 2500. Clean and inspect them. Do a leak down. Hardened Seats new Bronze valve guides. Oversize stainless steel valves three angle valve job port polish and deck the head. If it’s not a numbers, matching engine I would just get a nice set of Indy, aluminum heads. That will save you about 80 to 100 pounds of weight they will flow better and they ard easier to work on.