Those numbers are for 1967. 4120 is for 1966 without CAP. You have a good Top, and all you need is a correct bottom plate. They can be made from a 2 barrel truck air cleaner with the 10 inch air filter. 70' and 80's? The original carbs work best with the original intake, because of the small secondary holes in the intake. Unfortunately the original carbs use a smaller air cleaner base plate than Holley or newer Carters or Edelbrock carbs. Slantsixdan an was looking for a 2 barrel 10 base plate if you want to sell it.