1965 273 2 bbl engine.

the later manifolds can be made to fit but they are for the larger inlet port of the later heads ,so you will have a large step in the port ,not exactly good for flow,,i once found an ld4 inlet ,rare in the states no matter england ,someone had hogged it out to fit later heads ,i could have shed a tear .
i used a 2 barrel holley on my 64 with an adaptor plate ,runs very well