Dodge would have used either a Stromberg type WW or a Carter BBD in this time period on the 318.
The WW is an excellent carburetor, one of the very best two-barrels ever made at any price, any time, or anywhere!
While the BBD is not the best carburetor Carter ever built, it would still be superior to a Holley 2300 running through an adapter.
And in the 1970's, Holley did make a "price leader" type 2210 that MIGHT fit but like the BBD, not the best carburetor from this manufacturer.
Jon.