I have done this on 2 trucks and before I did it on each one I did allot of research.
1) try to lift the truck with just tightening the "pork chops" (keys) to the height you want.
2) if you feel you will need a little more buy a set of Ford pork chops, they are the same leveling pork chops that you buy form after market suspension companies, but they are 1/3 the price. Do some searching and you can usually find them for about $30.
3) if you want 3" or more out of the front buy a lift kit.
Tightening the keys increases operating angles on tier rod ends and ball joints and will cause those parts to wear out "Faster". "Faster" is a relative term and who knows how long your ball joints will last, they are just a wearing part of a vehicle. Your ball joints and tie rod ends could last 6 mo or well after the truck has gone over 300K milse and is sittin in a junk yard, you dont know. But it will happen "faster". Before you do any lifting you need to accept that it might cost you some parts sooner rather than later.
That being said I will do this to every truck I own if it is not done already.
Great article :
http://www.gmfullsize.com/tech/torsion401.html