I don't think he plans to do anything with them but practice.
Here is my suggestion:
buy or get a set of intake and exhaust gaskets, and either a marker or machinist dye. Put the gaskets into place, held in lightly with some bolts, and mark the areas of the head that do not match the gaskets. Start here, opening up the intake and exhaust ports to match the gaskets. You have to taper your work into the ports, merely opening up the first inch of the port is not going make any significant difference.
After that, pull the valves, and smooth the transition between the cast portion of the head, and the valve seats. Blend and shape the valve guide boss (bump in roof that the valve passes through).
Imagine it from the air flow side, the air wants to pass from the intakes to the head with little to not disturbance, alont the intake runner, make the turn and pass the valve. As such, the intake to head junction is important, the turn to valves (bowl blend and valve seat)is important.