Looking at the ridiculous amount of baffling on my 08 expy today...I really want the aem intake but they only fit the f150 (it says). Is there really much of a difference? I prefer the aem to the k&n so I may have to check out my stepfathers 09 f150 to see if its a similar layout.

 

Is the intake the only modification you're going to make?

Reason I ask is that the baffling on the stock intake is actually not restrictive, it's just a noise cancelling agent. The flow of the stock intake is actually very well matched to the 5.4L's performance, and the aftermarket intake will likely only give you gains, if any at all, above 5k RPM.
The aftermarket offerings are commonly referred to as "engine bling" for a reason...they provide little to no performance improvement over stock, but they might look better. Secondly the aftermarket intakes usually pull air from the engine bay, whereas the stock intake pulls from the fender well, which should be cooler air.
Honestly, you'd be better off going with a hand held tuner/programmer with custom tunes, as you're likely to see both performance gains and possibly economy gains depending on your driving style.

EDIT:
Here's a similar thread from just a few days ago...was right on the first page of the forum:
https://www.ford-trucks.com/forums/1...-worth-it.html

 

Thanks, I read that already. Ill put one on anyways seeing that my other 5.4 got a bout 1.5 mpg increase from an intake.

P.s. it sure seems like with all the baffles and ports would cause unnecessary air turbulence...thus slowingg flow down?

P.p.s. I still need to know if the engine bay between a 2009 f150 and 2008 expedition are similar enough to accommodate the same intake...I read the installation instructions and it sure looks the same. Would love to hear from anyone who tried it though!

 

Fair enough...it's your money!!

IIRC the 09+ F150 and the 07+ Expy share the same intake layout, but don't take my word as 100% accurate here. Go to someplace online like Autoanything or SummitRacing and put in your vehicle specs. That should help you narrow it down.

 

According to the instruction sheet for the K&N intake I have, it also fits the 2007-2011 Expedition. So the stock intakes must be the same.