Correct. To post a pic directly to the site you have to be a contributor for 13 bucks a year. You don't need to be a contributor however, to use another online image hosting site and then link to the thread. Works well either way.
That part would go to the frame side of an EB, as said, but is also the same one used on the draglink of a '78 or '79 full-size. Ford eliminated the u-bolt attaching and went to a bolt-on.
Paul