I hadn't thought about that....
If it says '3 valve' that would be a triton engine like the 6.8l Ari has in his Newmar coach.
FL 820 filter in that case, though I don't know what the filters are in the little ones.
FL1A was so universal, for SO long it's just what I think of when I think 'Ford oil filter'
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.