Got Shell 93 Octane and now barely idles 1973 Dart 340

I put in a half of tank of 93 Octane at Shell, which is the same gas station as last the time I filled up at and by the time I got home 4 miles later it will barely idle. If I close the choke or cover the primaries on the carb the idle speed goes up drastically and if I spray carb cleaner into it while running. I tried adjusting the A/F mixture but that does nothing. I checked 2 spark plugs and they look good. Vacuum gauge reading 7-10" when I normally have close to 16"

Whole car is shaking and can barely get into the garage. Carb is a Carter AFB competition series and might have a little cam. I don't know.

It back fire through carb once when I got home. I checked timing and it is at 2.5 Degrees BTDC per factory specs. Champion RN12YC plugs in there from previous owner but look good, no fouling. Checked accelerator pump and spraying fine.

It was running good this morning.

Please help.

Thanks,
Eric