As a machine shop guy for many years I'd not suggest people do their own head work. Our basic cyl. head valve job includes. Strip cyl. head, wire brush chambers and ports, mag. for cracks, check guides, surface, stem wear and valve head margin, check springs for equal length. Clean head and all parts in tank. Glass bead valves and wire brush. If valves are good grind in centerless grinder and tip. Install valve guides as required. Machine three angles on valve seats in head. Setting all valve seats at same height with seat in center of valve face. If all springs same height check a couple and assemble head with new seals, vacuum check all valves and ports. Bag and call customer. -+
Setting valve seats at same height makes getting spring pressure easier. I had a spring seat cutter made for facing the spring seat in the heads.
I realize there are people who will not agree with me about doing your own. I will say having been in the biz for 25 plus years retiring 17 years ago, I currently use five different auto machine shops to build engines. Each has either a person or equipment that make the drive worthwhile.
Excuse the ramble, what spring pressure are you shooting for? Steve (CTR)