I'm an ASE Master Certified Engine Machinist, I do know how to do it, have probably rebuilt over a thousand cylinder heads, gas and diesel, and I don't have two thirds of the equipment to rebuild cylinder heads.
To "rebuild" a cylinder head (without replaceable guides) the guides are bored out and "false" guides are installed, topped and reamed, then the seats are refaced or counter bored and inserts are installed and faced, then it's resurfaced, cleaned and reassembled with new parts.
I do have the equipment to reface used valves and face the seats, but I don't have the equipment to do any of the rest of it, the SERDI seat and guide center and ROTTLER SFO surfacer I used at the machine shop with tooling ran about $80K, I can't afford that for at home!
What kind of equipment do you have?
You can get more power out of ANY engine!!!
ASE Master certified engine machinist, gas and diesel