People also seem confused about whether to do this with the truck sitting on the ground or jacked up. There are pros and cons to either method. The correct method is the method that suits your situation tje best.
FoMoCo says to do it on the ground, but ask yourself "why?" The official procedure was developed for the benefit of the dealership service department, and they do things differently than a guy in his driveway. They do in an alignment bay, where a guy can walk underneath. More significantly, the tires will be on "floating" pads that allow the suspension to settle WHILE you are adjusting, so you can instantly tell exactly how high it is. You set it and you're done , exactly right, right away, and you're ready to move on to the next job. Time is money, so get it done and get it out and get on to the next one.
At home, there aren't any floating pads, so you have to roll the car a few feet to relieve the camber change pressure against the tire sidewalls, so you don't get 100% accurate real-time feedback while doing the adjustment. If you do it on the ground you can still see approximately how much it's moving, but you still have to roll it to see where it will settle. At home, the pros for doing it on the ground are less time spent jacking, and being somewhat able to see the effect of what you're doing while you're doing it.
BUT... those bolts can be a reat biatch! Especially if they've never been moved...
Jacking the front tires off the ground makes the adjusters a bit easier to turn. I counted about 80 "cranks" on my ratchet from top to bottom, which I figure is about 20 full turns. My arms literally fell off, poetically speaking. Anything that helps, helps, so that's why most people do this with the front jacked.
...and also why people who write procedures for dealer mechanics prefer their way. There are good reasons for either method, mostly depending on facilities.
