I think my other choices are plug color, exhaust smell and SOTPants, which will always change. Are there any other indicators?

Plug color is vague. Exhaust smell and performance are subjective.
Colortune documentation indicates "mixture at idle".

With wideband o2, I figure I can narrow the variables to 2 and collapse them, at a given rpm/load/~~, then see where it goes and spin my needles as required.

The Simons headpipe collector is way down the pipes.
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MPergiel, Walker, MI

What have you done to your motor? It takes a lot of modifications before the stock needles don't work.
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69 142S Overdrive + 69 164S Manual

Plug color is not only vague, it's pretty much useless. But that doesn't mean you can't come very close to optimum by reading plugs the correct way.

What you want to look at is the amount of soot on the insulator around the center electrode. If there's soot all the way up to the electrode, the mixture is severely rich. If there's soot partway down the insulator, but it's clean near the top, that's somewhat rich. The optimum setting is when there's no soot on the insulator, but if you went any richer, there would be. An overly lean mixture doesn't look any different from the correct mixture, so you may have to go back and forth a few times to really dial in the mixture.

Four or five minutes of halfway enthusiastic driving is plenty between plug readings. You don't have to do plug "chops" where you don't let the engine idle after a run -- a few minutes of idling won't affect the soot level (unless the mix is grossly off).

I bought a handful of cheap electronics and am going to build a couple LED A/F meters, just for kicks, following these instructions:

http://www.buckeyetriumphs.org/technical/Carbs/AFMonitor/AFMonitor.htm

Then, using this methodology:

http://www.mossmotoring.com/su-carb-very-fine-tuning/

and instead of the dynomometer, just mounting a camera to see the dashpot level, I can retaper the needles to fit the needed curve. LOL. At the current atmosphereic conditions, nonetheless.

Just kidding. The plugs are nice and lean. I just drive around town for now.


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MPergiel, Walker, MI

I think the wide band is the best. You can check the fuel ratio under load. I did pretty good with a regular old 02 sensor. I made a LED bar display for it. You don't have to build a display, you could just run a good meter.