Excellent info (as always from you) Arthur! Thanks for taking the time to type that all out.

My car is a manual trans (4 on the floor in fact).

Sounds like I'm not far off then:
1) I do know that it's a vacuum retard, but I didn't know the idle timing was adjustable.

2) Valves are freshly adjusted and I'll run through them again in 500mi since the head is freshly rebuilt.

3) Just prior to all this head work I replaced the balls and sockets and one transverse linkage rod bushing and then set the linkage so it was really nice and both the throttle plate and pump lever were moving in sync. Of course I had to run through that again today since it's all been apart.

4) The throttle plate stop is adjusted. I like to back off the screw, remove the linkage rod and spring and then gently rotated the plate until I feel it just touch inside. Then I bring the screw in until it just touches, and then maybe a 1/4 turn more to just lift the plate off the housing.

5) I've also got the power steering boost and the idle return damper and both of those are set to allow the pump and t-plate to return to their respective stops.

6) How you describe leaving the idle and mixture is how I wound up leaving it today. I was going up and down one click at a time on the mixture screw, then going for max smooth idle using my digital VOM which has a tachometer function. With a max idle in the 830-850 range and starting to get that "I'm too lean shudder" I was turning the idle air screw in until the idle smoothed.....as you say, leaving it slightly rich. But I was still getting a wavey idle. Sort of a rhythic up and down of about 75+rpm. No matter where I put the mixture screw it was still up and down with the idle. So I loosened the distributor clamp and advanced the distributor maybe 1/8" and it smoothed out and idle the best it's ever idled. I'll check again in the morning, but I think that put me around 0TDC, or maybe as much as 3TDC at idle. But still, after sitting for maybe 10-30min, it won't start unless I crack the throttle open. Then it fires right away, but has a lopy idle for a minute or so unless I blip the throttle, and then it clears right up and goes back to that nice 6 cylinder rumble.

7) Prior to all this work, I'd set the car up on the exhaust gas analyzer and had it at about 3.5% and 795 rpm. It was pretty rock solid. Still a little subtle miss at idle, but low speed cruise was fine, as was acceleration and sustained highs speed cruise. Based on how the exhaust smells right now, I'm probably closer to 5%.....but that's just a guess.

8) Sorry about the mis-info on the gear usage and pulling a hill under load. I meant to say that I'd be in 1st or 2nd at a slow speed and then go into 3rd and stand on it.

9) I'd like to try your vacuum gauge idle adjustment method. I've never done that.

10) So I guess the plan tomorrow will be to set the timing at 30BTDC and then I may fatten up the mixture a click or 2 more, adjust the air screw to drop back to 800rpm from the 850-875ish I get with more fuel, and then see how it's starting hot. I guess one thing I could do is disco the pump rod and see if the hot start wants the throttle plate open = the engine is too rich. And then disco the t-plate rod and put the pump rod back and see if the engine is wanting more fuel when hot.

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