Your ‘72 318 may have the factory iron single plane intake. If you’re going to use it, take it off and get the inlet area milled open. If I ran a four barrel adapter, i would probably use one of the small pattern two barrel to large pattern two barrel adapters to bolt the four barrel adapter to. But if you could find a used Weiand stealth or Edelbrock LD4B you’d be way better off. Im guessing you’ve got the open chamber 318 Mopar heads to be able to set up for conventional valve springs and retainers up to eliminate the exhaust rotators.
