67 barracuda with a 383, need help!

Assuming your OEM rad was in good shape it was not the issue.

Ditch the electric fans and go back to a stock fixed 7 blade and shroud setup with OEM HP cooling radiator.

I'm assuming all of the pulleys and water pump are correct for the application
Was OEM but not an original 383 car. Would an OEM for a 383 67 work? Thank you for your advice!