A) and then C) if you can't make it work.
If you have heat problems the LAST thing you want to do is not have a fan shroud.
Pics would be great.
If you need to slot or drill a new hole I'd suggest using a fender washer under the head of the mounting screw(s).
Does the extra ~3/4" put the shroud opening back
behind the fan?
I know when my shroud cracked through I didn't feel like taking the fan off, so I trimmed a bit at the bottom and slipped it in at an angle while using the uneven blade spacing to get it into place.
But always best to hang the shroud over the fan while you drop the radiator in, then move it forward and attach it.
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.