-64 A body manual steering box

It is my understanding that early A body boxes used bushings. (Oilite) As the original designers did not anticipate heavier V-8 engines in A bodies, only slant sixes. Later they upgraded to bearings because Mopar engineers are thorough and didn't do things half-assed.

I'm 95% they are interchangeable as long as the Pitman arm splines match. A 66 and newer would be an upgrade.