DJ Mindframe, to get up and over 2" of lift, this will take some work. You can max out the torsion bars as they are now by simply taking a 18mm (?) socket with wrench and turning both bolts in the tighten direction by the same number of turns. I would start with the driver's side as that is going to be the more limiting one. Count the turns on one side and then turn the other side the same number of turns in the same direction. Tada, done. Don't forget to roll the expy a few feet right after doing this as you have caused the tires to shift a little and you are putting additional stress on the suspension until you roll the truck (you are forcing the tires under the truck a little bit). May be advisable to get an alignment done if you are putting in more than 6 full turns. Less, should be good. Steering wheel will tell you if you have a problem or not (wobble side to side as you drive that gets worse the faster you drive).
Now, to get the 3" like you are wanting. You will need to following things:
-high lift jack
-tall jack stands (enough to hold the wheels off of the ground by atleast 3")
-18MM socket wrench (see above)
-short piece of metal rod to use as a punch (1/2" to 1" in diameter, about 6" long)
-Big F'n hammer
-PB Blaster (apply some at each end of the torsion bars once a day for 3 days prior to doing the job, TRUST ME, YOU WANT TO DO THIS!!!!!!)
-torsion bar unloader tool (can be rented from any auto parts store for free, just need to put down a deposit)
Now, for the job. What you are going to do is to lift the front end of the truck up in the air high enough to get atleast 3" of clearance under the tires (more is better, about 6-9 would be ideal). Support the truck by the frame (not the A-arms) in this position. Using the socket wrench, count the number of turns that both of the key bolts are screwed in (this is vital information, not counting can result in the truck not sitting level once done). Write down the number of turns for each side!!!!!!! If needed, use the torsion bar tool to take the load off of the supports that the bolts screwed into. With the keys off of the supports, push the supports out and then ease off of the torsion bar tool to remove all stress off of the torsion bars. At this point, you are going to need the metal rod and the hammer to push the torsion bars forward a few inches. When the bars move forward, the torsion bar key will remain inside the channel of the crossmember. once the key comes off of the torsion bar, drop the key down, find the key that is identical to the one you removed (except for the center being rotated slightly) and then put the new key on the torsion bar. Now, from the front of the truck, push the torsion bar back to where you found it. Using the torsion bar tool (will be needed now), push the new key up a little bit till you can slide the bolt support back into the cross member. Remove the torsion bar tool, insert the bolt (counting the number of turns) and tighten the bolt till it is installed the same number of turns as you found it. Repeat for the other side.
Your big problem is going to be getting the torsion bars broken loose to slide forward a little bit. This is where the PB Blaster is going to be your friend. You can either bust a knuckle trying to beat the torsion bar out or spend a little time using the PB Blaster. Your call. You may still find the torsion bar a little bit difficult to move even after spraying it a few times.
Any more questions about installing the keys. It is pretty straight forward once you start doing it.