Ok that makes sense, so the rockers are cast differently? The rod adjuster hold is basically cast to far over to one side for this rocker location.
Just searched and it seems all pre 1952 rockers are the same, and then there are 2 generations of 235 arms. Seems that the other rockers have a more symmetrical casting.
who can I contact for a single used arm to swap on? Seems to be only whole sets on ebay. Thanks!