G'day Sir Kev
Just done a google check and found that a 2005 F-250 has a track of 1745mm at the front and 1729mm at the rear.
The 100 series has a track of 1620 mm according to the site I was looking at.
So thats only about 2 inches per side, shouldn't be a problem once you allow for the width of the tyres.
Cheers
JGM