Welcome to MP3Car!
Nice to see another Super Duty here. I don't know if retro fitting an '11 Nav unit into an '05 will work and I doubt you will find many people here that are totally familiar with the nuances of what Ford may or may not have done to allow this to work. If you have not already done so, I would suggest you post the same question at thedieselstop.com . There are some extremely kowledgable people on that site with Ford Super Duty specific info. If someone on here does have the answer, I'm sure they will chime in.