I was able to find a salvageable head on ebay ($102 shipping included), it even had all the valve shims still in it. Let me start by saying, rebuilding this type of head became a series of compromises, there's 20 valves at over $50 each and guides are over $20 each, so finding the best of the two heads became my only option to recondition without spending $800 - $1000.
I had to replace 3 valve guides (cmsnl), all were intakes and all the middle valve in the configuration (
?). All the seats were serviceable but the intake valves were beat up. So I went thru and picked out the best 12 of the 24 in front of me. Once the head was disassembled and the 3 guides replaced, I went about rechecking all the valve and seat interfaces just to see where they were showing on the valve face. All were seating out at the margin of the valve so after some conversations about what might be the best approach I decided to only use a 45 degree cut to clean up the seat and then a 30 degree cut to narrow the seat down and to the the center of the valve face. Part of my concern was removing alot of seat material and then having to shim the springs and then find all the right valve stem shims ($8 ea) to get all the valve gaps in spec. It starts to add up.
This process of cutting the seats took the better part of the week as I was working with one of my machinists at work to get this done, and we only had about an hour time each evening. Once the seats were done, I lightly lapped each valve with a fine lapping compound to confirm our seat location on each valve. Whew! 20 valves. Re-cleaned the head then reassembled using new valve guide seals (again, 20 of them).
Let me take a step back, to get to this point was time intensive, when disassembling this head, everything has to be documented (gaps, shim sizes) and returned to its original position when reassembling, every seat and valve is checked for runout. Then once the seats are cut you have to reassemble and remeasure to determine your next shim size. The exhausts were not a problem, the intakes became a little more intensive. 1st swapping out all the intakes contributed to this, I measured each valves overall length and found that there was very little variation in length (.001-.002) but there is some, so it's a problem. The 1st reassembly on the intakes was interesting, I had no clearance to .0025, all well under the .0043 minimum. Long story short, was able to locate the correct shims (used) and bring the intakes gaps back to spec. But it takes time and patience.
Now I've got to replace the #1 cylinder sleeve, its got a bit of corrosion that can't removed w/o going over sized and o/s pistons just don't exist. So once that's done I can start reassembly
I like to have attached more pic's but taking pic's thru this was really the last thing on my mind.
