It sounds like these might not be aligned properly. You may need to see if the dealer can add some positive caster while still staying within Ford's specs. I had this same type of issue with my F350 and that resolved the issue. The dealer aligned it to Ford's specs and it was still like driving a motorboat on the road. I asked the dealer to add a little bit of positive caster while staying with their specs and it was resolved.
Here is a link that describes caster and you will understand why this brings your tires to center. It's like a grocery cart. You are pushing it from behind but the wheels should go straight because of positive caster.
Hope this helps.