I wouldn't use the NAPA one's either. Only fuel filters that should be used are Motorcraft, or Internatinoal. A lot of the other companies, even though they fit, don't even have the water separator on the lower element.

 

After I had an injector replaced that died in a glorious hail of smoke and sputters, I eventually got codes for all 8 injectors circuit low, including the new one. The root of all of this evil, a bad FICM. I ended up replacing it with aunit out of an 06. My research has revealed to me that all 6.0 FICMs are pretty much interchangable.
If you're referring to mounting screws, my March 03 6.0's FICM mounts with 4. I'm pretty sure that I am off base because my electronics knowledge is pretty low. Didn't think it would hurt to offer it up since you're reading this anyway.

 

Karl, when we say 7 screw or 4 screw, we're referring to the amount of screws or "pins" under the inspection cover on the FICM itself. The old models had 7, the newer one's had 4. All FICM's were mounted using 4 bolts/nuts though. Though the 03 models had a really nice aluminum bracket that bolted to the valve cover solid, and then the FICM was rubber mounted to that. Ford then changed the design (I assume due to costs) and used stamped steel mounting plates that were rubber mounted to the valve cover and then the FICM was solid mounted to that.