"I am still wondering if swapping out the 40% secondary linkage to the 60% delay may help a touch."
I have never played with mods to the secondary linkage, so take what I say with a grain of salt. My understanding has been that the secondary opening progression tuning was for part-throttle racing such as road racing.
It seems you have a nice bag of tricks to get the WOT AFR were you want it. One more thing you may want to consider is decreasing the secondary MAB, instead of increasing the jet. You could go back to 75 or 76 jets, and try decreasing the MAB a few steps. This will change the slope of the fuel curve, and could be useful if the AFR is good at lower RPM but not where you want it at higher RPM.
Update on my problems: I tinkered some this weekend trying my smallest MAB (.025) and the largest (.035), just to see the effect. The big AFR swings were still present under all tests at highway speed. The smallest MAB moved the range of AFR lower (centered about 12.3) as expected, and the largest moved it up (centered about 13.1). At this point, I am thinking there is still some sort of an ignition problem, and the rich dips are the result of a miss. My wideband is a little slow, so it is hard to correlate what is shown on the meter with other sensory input. If I really focus it seems I can hear some subtle farts in the exhaust note at highway speed.
At first I thought it might have something to do with my 6AL-2, since highway speed (3K) is right when it drops the multi-spark. However I need to do more experiments to see if I can determine if it happens at a specific RPM or conditions. I haven't been able to notice anything at speeds in the 45-50MPH range. Any thoughts on what could cause a light throttle miss at higher RPM?
