Cut them apart and see the difference. Nothing made by FRAM will ever go on one of my vehicles. Wix or Fleetguard.
I've done this with the screw on frams, and you are right. However the filters we use on our 6.0's look identical...nothing to cut in half here, you can see inside and out. They're not a screw on type.
I ran a fram filter in my truck one time and at 4500 miles it colapsed and i lost all of my oil pressure. I'll never use another on.
Ya it was in an 03 F250. They look identical but i have never had any problems other then that one time.