I'm sorry, but this just isn't true. I've grown weary of all the misinformation out there about these trucks and the damn UCAs. Stop drinking the Cognito Kool-Aid. How many upper ball joint failures on these trucks can you find on the internet? - only a couple out of the thousands and thousands that are lifted.
Again, the control arms can only move so much as they are bound on the upper and lower end of their range of motion. The ball joints and axles are still operating within this travel envelope no matter where the static starting position may be; i.e. lifted trucks are going to have a static position toward "more droop" to achieve the lift, but all the components are still within the normal engineered range of motion as designed by GM. GM even adds longer axles to compensate for the increased distance from the diff to wheel hub. There is no need to swap the UCAs because they are still within range.
Jack up your truck and take a front wheel off. The suspension is going to droop to the stop. This is going to be the case whether the truck is lifted or not. The factory GM upper ball joint is designed to operate within the range.