***Mods, please sticky***
Seems like we are getting two or three threads per week on this topic so I thought I'd create a reference thread. There's a ton of data on the web written by folks more knowledgeable than me, I'm writing this specifically for the F150 owner looking to make an informed mod purchase.
For the purposes of this thread, lets just agree that anything past factory travel up to ~16 inches is Mid Travel and Long Travel is ~17+. There are numerous opinions and marketing labels out there but it's still a topic of debate because there is such a variance in stock travel across vehicle brands. Toyotas for example can pull more than 12 inches with just a UNI upper while Fords are limited to about 9, and that's with an upgraded UCA (UNI).
Travel is simply the entire range of motion (arc) of the A-arm - compression to extension.
Up travel is compression
Down travel or extension is droop
When considering suspension modifications you need to take into account two things; what are your goals and how much money are you willing to spend.
The least expensive route is a Uniball upper control arm (UNI UCA). The factory Ford arms mechanically bind at about 8 inches of travel. Adding a UNI upper will net about 1.5 inches of droop travel by eliminating that bind. This mod is a mechanical mod only, it has no impact on ride.
The next step after the UNI upper is a more robust coil over. Brands: ICON, KING, FOX, Bilstein, SwayAWay. There are others but those are by far the most popular. Adding an upgraded coil over is a 'dampening' modification, it has no impact on length of travel (clarification - if the shock isn't sized properly it can limit travel but they can't increase travel, that is a mechanical function). It WILL make the truck ride better and will handle rough terrain at a higher rate of speed than stock. For just an upgraded upper you'll need a factory replacement size coil over. For a MT/LT kit you will need an appropriately sized coil over.
I know ^^^ that ^^^ isn't a truck but it illustrates very well the travel arc. It should be apparent from looking at that image that the longer the control arms, the larger the arc and thus the more travel you will achieve.
Side note - one of the limiting factors for travel on 4WD F150's is the axles. They can tolerate only so much angle before they bind. There are better/stronger axles out there (RCV) but they are very expensive ($2,500).
The next option for more travel is longer arms.
Raptor arms are longer than non-Raptor arms and will net 11.5 inches in stock form, close to 13 inches with an upgraded UNI upper. They are a lower cost option for non-Raptor folks and WILL, I repeat, WILL bolt on in place of your factory arms. The spindles are the same so no issue there.
Side note - there are only minor differences between the 04-08 and the 09-14 frames, Raptor gear will fit those trucks as well.
Several companies (BRENTHEL, Dixon Brothers, H&M Racing, RPG, Outlaw Raptor, etc...) make MT kits (a couple are LT kits, pull over 19 inches, but all are advertised as LT). You are looking at 5k minimum and as much as 20k for one of these kits.
You will break 10k to MT your truck (f&r) unless you use Raptor gear. MT coil overs and shocks are ~5k by themselves.
Side note: longer arms require longer tie rods, axles, brake lines and wider fenders. Raptor axles will work with 09-14 but not with 04-08, spline count is different.
Now the easy part, the rear.
Deaver or National leaf springs (~1,200), bypass shocks (~2,200) and a set of bumps tops (~1,200 for frame reinforcement kit with bumps) - you only gain down travel for up travel you'll need to notch the frame. You'll need new bedsides if you go with larger tires, 37's will hit on a good jump.