318 rough idle (20+ years in storage)

The ethanol removal method you mentioned, I found several years ago on a website about ethanol fuels. The main thing is that ethanol is an octane booster, so the resultant de-ethanol'd fuel will have a lower octane rating by a few numbers. They also had some ethanol concentration test kits on that website, too.

One other thing they had on that website was which (at that time, about 10 years ago) fuel additives/octane booster/fuel-drying agents contained alcohol. No reason to add a fuel octane booster to a fuel from which the ethanol had been extracted, as that would defeat the whole purpose of removing the alcohol in the first place.

There are various additives (as the Lucas Oil "Green Stuff", as I call it) which counteracts the affects of ethanol in fuels. Perhaps the addition of outboard motor gasoline oil might do similar? 1oz per 5 gallons concentrations.

The particular style of Carter BBD has been around since at least the earlier 1960s. It is a metering rod carburetor, rather than a "fixed jet" carburetor. Fixed jet carburetors need other orifices and such to get a better fuel calibration curve over the full spectrum of loads and engine rpms. With metering rod carburetor can do that too, just by varying the size of the metering rod from idle to WOT and then within a particular jet size. The later AFBs and AVS used a power piston which worked against intake manifold, via a calibrated spring, to do similar things. The TQuads used a hybrid situation, where the power piston was working against calibrated spring pressure, but had a positive stop on the bottom of the power piston, which had a positive stop on the bottom which contacted a paddle which was operated by a cam on the primary throttle shaft, so it could only go down so far no matter the manifold vacuum.

From what I've seen, there are no calibration kits available as there are for the AFB and AVS carburetors, even when Carter was Carter. Few people with 318 2bbls were apparently concerned about those things, then or more recently. Chrysler did have part numbers on the jets and rods, with some specs on the rod diameters in the FSMs, in some cases.

I have seen some forum posts in other forums about the knockoff carburetors (as the Rochester QuadraJets). In some cases, the fuel calibrations as supplied had to be completely re-done in order to get the desired performance and drivability from them.

I would wait to purchase a fuel/air meter until you had run the car more, so that you could see how the spark plug ceramics colored. If they turn chalky white, that's too lean. If a normal white trending toward tan, tha'ts fine.

The earlier gasolines we had in the 1970s, pre-ethanol in the present concentrations, would yield an ideal air/fuel ratio of 14.7 whereas the current E10 fuels need 14.2 for optimal results. The Chevron gasoline website used to have a very informative section on "ReFormulated Gas", back in the earlier 1990s. It has since vanished from that website. It mentioned their extensive testing on the then-new RFG. RFG had an almost even split between MTBE and Ethanol. When MTBE was discovered in trace amounts in municipal water supplies, from ground water, it was removed, leaving the E10 fuels we now have. Ethanol advocates have lobbied for E15 for many years, touting claims which are marginal at best, NOT mentioning an even further reduction in fuel economy although its price is few USD cents/gallon less.

When the Chevron RFG came to TX, I was daily-driving a 1970 Buick Skylark 350 2bbl. I kept track of the mpg with each tank as my driving was consistent. I did document a 3% fuel economy drop with the RFG, which is what Chevron claimed would happen. No significant differences in drivability from the normal gas which came before it. That particular car was one which my great aunt purchased new in Los Angeles, so it had the leaner carb calibrations than USA-Federal emissions cars did. Still, I experienced very little to no issues with RFG or E10 in later years. Others apparently have, though. I have not re-jetted any of my cars, either, as the spark plugs still looked light tan, just my experiences.

Just some thoughts and my experiences. Happy Holidays!