First, cranking up your torsion bars does absolutely NOTHING for suspension travel. All it will do is put extra strain on the CV joints (although you will be hard pressed to find anyone who will tell you it has happened - or at least will admit to it!).
This is sort of a comparison to apples and oranges... Cranking up your torsion bars only will gift you a little clearance for tires, but will make your ride rougher and "bouncier". You are, in effect, changing the spring rate of the front end to be more responsive. This can wear out shocks and CV joints more quickly than stock height.
A "lift kit" only provides you will a drop bracket for the front end and will usually come with some kind of longer a-arm, either upper or lower, or both. This doesn't even really give you much travel either, but some. After that you are just, again, cranking up the torsion bars to get lift. The drop bracket for the front end is the key, as it will keep your CV joints and stub axles more in line.
Sorry this is long, but I have feeling that most folks aren't getting the difference between cranking up the T-bars and a "lift kit".
By the way, I use "lift kit" as a generic term. If I had the knowledge and expertise (oh, and money), I'd be running longer a-arms, bigger torsions, reservoir shocks and pre-runner rear springs...
But I might just end up getting another truck!