1972 duster original a/c

I put a factory air salvaged from another car in my barracuda. I bought an expansion valve, dryer and condenser coil on eBay as a package deal, I think. You don’t really need the vacum ball, older models didn’t have it. The hardest part is finding the lines, brackets & pulleys. if you don’t find the factory stuff reaso, you might be better off with an aftermarket compressor setup.