The purpose of the Upper ball joint flip is to reposition the upper A arm at a better angle to relieve binding that occurs with the upper ball joint from extreme torsion bar cranks (lifting the front by cranking the torsion bars). When you lift using this method you are twisting the lower A arm so it pulls the front tire inward and pushes the front of the frame up. This causes steeper angles on both control arms and result in the stiff bouncy suspension cycle. The upper ball joint flip help the upper A arm and ball joint not be at such a steep angle and allow the suspension to cycle up and down a little better and smoother.
The upper ball joint flip only applies to trucks with torsion bar front suspension( 1st generation 4wds and 2wd z71s)
Open up the glovebox and locate the silver sticker. Scan through the codes. Somewhere in the series you'll see either Z71 or Z85. That will indicate which suspension package you have. All 4x4's are torsion bar front suspension.
A common suggestion is for the individual to crank the front end up with stock keys to determine the amount of lift that is available. If the desired height is not achieved, then look into the keys. If the height is fine, then all you will need are the shackles. A footnote to the lift height though is that you should try to keep the measurement from the center of the front hub to the fender lip around 24". There is a bit more available, but the ride becomes more compromised in the upper range like that. That is similar to measuring how far the bottom of the fender is from the ground, but you are measuring from your hub, not the ground.
Take note, adjusting your torsion bars will require a front end alignment. So it isn't recommended to experiment with the lift until you are ready to move forward.
You can count the number of turns you turn the bolt, then undo it the same amount. That will return you close to the current alignment spec, but not exact. Close enough for you to drive around while making decisions and ordering parts.
I just did this on mine and I noticed a good difference on the ride quality. Mine is only raise a 1.5 inch from stock. Between the rancho shocks and the upper ball joint flip I was able to back off on the torsion bars giving it the perfect balance.
Just call suspension maxx and they can make them and send them to you with very detailed instructions. I did this to mine so I could get my truck aligned, because if you crank the front up all the way or even three inches, it's hard to get the camber to align without the flip.
With a 2005, it is more likely you will need keys. Torsion bar springs will sag over the course of time limiting total height of the stock keys.
As I mentioned in my previous comment, use the fender/wheel hub distance as your guide. Not the net lift amount. On a new truck, 3" may be too much. On an older vehicle, 3" may not get you to what is considered to be 'max'. Lift it to around 24" from wheel hub to fender. You can get up to 24.5, but you start asking for trouble. But it IS possible.
At that height and above, you won't be able to get it to align within spec (or it will be challenging). And the ride is pretty hard to deal with. 24" still aligns perfectly.
Agreed with above that flipping the ball joint is a recommendation for that much torsion bar lift.
Suspensionmaxx is a great product, and you will receive a discount on your order if you tell them you belong to 355Nation. You can get your shackles, keys and spacers for the ball joint flip (which is sometimes preferred).
I actually have ball joint spacers installed on my truck...it helped with aligning it.
Take note, you can lift the vehicle today and get an alignment. But if you choose to ball joint flip in the future, it will require another alignment.
As for the link you posted.....most of the products are the same. A torsion bar key is a torsion bar key. Variations come in the quality of the shackle. With that said, Suspensionmaxx does make a very good product and I would recommend them if you are asking.