thanks rich, those pictures are very helpful. it sounds like the first gen box needs those different pitman and idler arms with stop lugs at the end. the fact that the replacement box's pitman arm does not have the lug (it is identical to the installed one) tells me that it does not depend on external stops. great, done! now to continue with the swap job.

FWIW, on my workbench, the arm rotates about 75 degrees from stop to stop.

__________________
'77 240D, 504H, OM617.952, etc.