Ok maybe Matureo or Stretch can answer this another member has a box from an 83 240d 123 chasis the # on the box is AK3350 with 53 sideways since the first letter is (A) I read this means the box has an internal stop. My box off an 85 300sd 126 chasis the # is V5093 with 43 sideways would the box from the 123 chasis fit on my 126 chasis if I use the pitman arm that was with mine or are they not interchangeable? Since my 1st letter is (V) I think my stops are on the chasis cross member which I can see. Would the A box fit in mine but mine would not go in the 123 chasis. Am I clear that on installing another box that you keep a centering bolt in it so it does not get off center? I am working on installing another engine and am trying to clear up and stop leaks one being the steering box.