1968 Dart Air Cleaner Housing

Yup that's early to mid 70s.
Note that if you want to swap out the 1 barrel your existing air cleaner won't work anyway, as the throat on any 2 bbl or 4 bbl will be bigger.
I have one here that says "CHARGER 225" that I wanted to use but unless I modify the base or make a different one I can't use since I am going to a BBD.