New to site, new to Mopar overheating issues

All good suggestions but I would start by confirming what size radiator you have (number of rows, condition, part number) since this is not an original set-up. Welcome to FABO.
It looks like a 22" but best to measure to be sure. My 318 Swinger had the original 19" 2 core with dealer installed a/c. A bigger radiator wasn't part of the kit apparently. I kept having overheating issues with the a/c on. I changed to a 22" and all is good.