You will notice my steering arm has a tapered hole at the bottom for a tierod end. (I drilled it out to 5/8 for a spherical rod end and bolt though) The normal circa '56 arms have a ball on the end that goes into a spring loaded socket, so I am using what I believe to be a '59 steering arm, and Ford made the change to a tierod end sometime in there.

I have also seen two different methods of Ford attaching the pitman arm to the shaft. One method is a splined shaft with a nut on the end, and the other is the type I have, with the large bolt going across the top and cinching the arm tight to the shaft. Don't know when these changes occurred though.

Don