To the question of 'will the IFS live' -- sure. It's fine as long as you aren't getting crazy with it.
But there are a couple issues created by IFS lifts. Keep in mind that these are all relative to the amount of lift -- the more lift you attain = the greater each of these problems will be.
First is the fact that as your steering knuckles are moved down relative to the centerlink/draglink. When torque is applied to the front tires, the tires try to toe in -- the tie rod ends and centerlink prevent that from happening (assuming the components don't bend/break). When the tie rod ends and center link are all parallel, forces placed on them are acting against each other, so those forces are almost entirely absorbed by those components - very little force is transferred to the idler and pitman arms.
For an easy to understand analogy, consider your arms to be the tie rods, and your collar bone to be the center link. Hold your arms out strait (lock your elbows), parallel to the ground. You have a relatively strait line from one hand all the way through to the other. Have one person push on each hand (push strait towards the opposite hand). Your arms / collar bone easily absorb the force -- just like the tie rods and centerlink do on your truck.
When you lift the vehicle, you invariably lower the steering knuckles relative to the centerlink. You no longer have a strait line through all 3 components. When torque is applied to the front tires, they try to toe in (just like they do in an un-lifted vehicle). But now, the tie rods / center link are not all parallel, so some of the force is transferred vertically through the center link, where the idler arm and pitman arm is forced to deal with it.
Back to the arm/collar bone analogy -- if you lower your hands so they are 18" below the shoulder, still held out to your sides with your elbows locked, then have someone push on each hand, strait toward the opposite hand, you will find it much harder to keep your hands in one spot -- they move towards your body and your collar bone gets pushed up. That vertical force is what the idler and pitman arm are forced to deal with -- and it causes wear and handling issues. The greater the angle between the tie rods and centerlink (or your arms and collar bone), the greater the problem.
The second problem is that the upper and lower control arms (A-arms) will be farther down in their arc. Problems here are two-fold. First, the ball joints are now operating closer to the edge of their travel limits, making it easier to exceed those limits. Lift kits that replace the upper arms generally correct this. The second problem with the arms being lower in their arc is that it causes excessive camber changes when the suspension cycles. When the arms are parallel to the ground, there is little horizontal movement for each unit of vertical movement. As they move away from parallel (to the ground), the horizontal movement increases exponentially relative to the vertical movement. This is compounded by the fact that GM uses a shorter arm on top than on the bottom (shorter arm = smaller arc radius). The result is that the upper arm sees more horizontal movement than the lower arm -- the result of that is camber change. Kits that use drop brackets to lower the arms (rather than just indexing the torsion bars) minimize this problem by keeping the arms close to their OEM relationship to each other and the ground -- but they also greatly increase cost and complexity.
The third problem is that the CV joints (half shafts) are now operating at an increased angle. The greater the angle, the weaker they are. Also associated with that is increased CV boot wear. Once the CV joint is operating at such an angle that causes the pleats in the boot to rub together, the boots wear quickly. Some aftermarket boots have fewer pleats, and therefor allow you to run them at greater angles before the pleats rub.
The lift kits that lower the control arms often also lower the front differential, which helps reduce the angle that the half shafts are operating at. Of course this causes the front driveshaft to operate at a greater angle -- depending on the amount of lift, the CV joint on the driveshaft may be compromised.
The further you push any of those angles, the greater the problem will be. If you are only looking at an inch of lift, you probably aren't going to see drastic changes is handling and wear. If you are looking for 3", you will see dramatic changes (bad changes) unless you address the suspension (drop brackets) and steering geometry (longer tie rods / shorter center link, etc), CV joint/boot wear, driveshaft issues, etc.
