Here's what I know - I went and asked when I took my truck in for routine service.
The local dealer here sells chips, pullies (pulleys???) , traction bars, etc and will install them on your truck. Here's the punch line. They will warranty the part they install on your truck for 12/12, however, if you bring it in for engine warranty work AFTER THEY INSTALL THE CHIP (or pulley) THEY SOLD YOU IN SAID TRUCK... they will outright void your engine warranty.
I believe that Ford (for reasons unknown to me) has given the dealers WAY too much latitude in voiding warranties and may even be encouraging the regional/area reps to void warranties to save themselves engine repair money "legally".
If I choose to mod my truck, I understand I do it on my own. The "pay to play" syndrome. But there is some kind of limit here... To believe that any modification, however minor, will result in a voided warranty will eventually drive business away from Ford and into the arms of the competition (course there IS NO truck competition

).
About 10 miles away, the local BMW dealer will sell and install Dinan performace parts on your BMW and the parts AND the car warranties remain intact and the car still qualifies for extended warranty purchase. They will NOT extend this latitude to parts not sold AND installed by them. (Again, I asked the service manager.)
My wish list (Hello, FORD?) is that Ford Corporate would publish a list of performance modification parts that THEY (Ford) will sell and install without messing you over on the warranty. Failing that, creating or adopting a "sister company" that would do the sales/work for them and Ford would continue to honor the powertrain warranty and the "sister company" would warrant the aftermarket parts.
Please, please don't think I'm trying to flame or smart off. I just wonder if anyone else feels the same way. And if, just possibly, there is someway to get Ford to take notice and at least meet us (performance drivers of "expensive" performance vehicles) part way (in the middle) on these issues. At the very least there should be some communication mechanism between the customers and Ford to try to work out some arrangement on these issues.
I love these trucks, the smile is huge and the thrill is wonderful. I'd like to put in a 2 way chip with one side for a "bypass" or only stock (or only slightly better than stock) performance -- daily driver mode -- and the other, to be used maybe at a maximum of 5% of the time, to be a more agressive street program. This is my daily driver and it works perfectly for that "as is", but for those occasssions when I need/want it, a little bit better would be a LOT better....
With respect to all.....