As an alternative, have your machinist install bronze valve guide liners in your existing valve guides. These are old heads, prone to cracking, so you want to be gentle with them. I no longer try removing the stock valve guide unless absolutly necessary. Have not done it for quite a few years now. I dont like to pound on the heads to get them out and in. The liners are much easeier on the head and minimize the chance of initiating a crack.
From there, the machinist should be able to machine the tops of the guides for PC (short for Perfect Circle) style Teflon seals. Your machinist can then dial in the right amount of clearance between the stem, guide and seal to make sure the valve gets sufficient lubrication. If you look closely at the next to last photo you can see the blue Teflon seal. That head is currently installed on a 261 that I ran down the historic beach bend kentucky dragstrip this past weekend at the trifive nationals, shifting at 5800 rpm. My son and I made 20 passes this year, 25 last year. Does not smoke one bit, and the valves get just the right amount of lubricant.
