Performed the Gotts intake mod last night on my 2001 Scab 5.4l. so far so good! Install didn't take long at all. I've noticed a couple degree reduction in my IAT. Driving after idling for a few minutes IAT drops quicker than before. The seat of the pants Dyno feels a bit quicker throttle response and the engine doesn't seem to work as hard at highway speeds. Time will tell if it helped out any on the MPG. All in all I believe it's a great mod to do for next to no money at all. Parts cost a total of $10.
A little update. Made a 200 mile round trip earlier this week. The truck seems to be happier on the highway with this mod. Idling in traffic the IAT still climbs up just as before but cools down much quicker once you start moving than before. Engine pull is smooth all the way through the RPM range and no codes of any kind have shown up (pending or active) I would recommend doing this mod to any Ford you could. MPG has increased very slightly. Not Enough though that I'd say this was worth any real savings in that area. Happy modding fellow Ford truck Enthusiasts!
Anytime, I just hope everyone gets some useful and needed time modding their trucks.
Later in mod update: MPG has picked up more than .5 gallon. Engine still runs smooth as ever and IAT still stays about 4° below ambient temps at highway speeds. At least according to my Superchips Vivid Linq and outside temp display in the roof console.