I've got to ask if this is a Windsor truck with a mechanical clutch release shouldn't the bellhousing
and everything inside be the same as a 4.9?
Gary shows a part number E3TZ 7515-D in
this post.
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.