I'm pretty sure the brackets changed too.
About the time the front of the frame rails got the 'crush zone'
But there's nothing special about the brackets, and they are available.
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.