A potential problem with Super Sixing my 1973 Duster.

There was an air cleaner housing specifically for cars with A/C; it has a flatted area on the front of the housing to (barely) clear the compressor. I don't remember for certain, but the first year Chrysler started using Sanden and Nippondenso round-body compressors on some RWD applications was right around the first year ('77) the Super Six was available; it might be the case that the Super Six cars used those compressors rather than the chonky Chrysler V2/RV2 item.

(There was also an air cleaner housing specifically for Dodge vans with the 225-2bbl; it has an offset base—the carb is not smack in the middle of the baseplate. This, if you can find one, can give ample clearance for whatever A/C compressor you might run).

See this thread for kickdown options.