Hard to imagine the person who took it apart would go to all that effort.
Even if they forgot where the arm went, they know they didn't take a bunch of parts off.
And just holding it in place gives a good idea where it must pivot from.
Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.