Ok the options on rear lift are the add a leaf and the extended shackles. Also the slr spring pack but that is another matter. Now I know they both provide a few inches of lift but I want to know how they affect performance. I know the shackles will cause your springs to sag but will they keep improving your articulation. I figure the aal will pick you up a couple of inches, but I would think your gain in articulation would be less than the shackles. Tell me if I am wrong.

Also I see all lift kits offer torsion bars and I want to know if there is any difference. Do they all offer the sway away bars or is there some difference between them.

I am not convinced extended shackles make your springs sag. Carring a lot of weight, hard wheeling, and lower quality OEM springs make them sag.
I've had mine on since summer and have not had any sagging issues.

Springs settle and sag over time, face it. but don't be completely misguided. If extended shackles caused all springs to sag out, why do jeeps use these kits.

Removal of the sway bar and longer shocks will improve articulation, not so much the aal's or shackles.

I think that's right... anyone?

1) Shackles and Articulation
Articulation is a factor of many things. In looking to improve articulation you must first find what is limiting it. The first place to look is bumpstops (compression) and shock length (extension).

Leaf springs will limit articulation if they are too stiff to allow maximum compression.
This is why sway bars limit flex.

Shackles will only increase articulation if the lift they provide keeps the axle of the bump stop AND extension isn't limited by the shocks. In other words, don't look for any flex gains by just shackles.

Also keep in mind that a shackle only lifts the vehicle 1/2 the length of the shackle length increase. This is because you are lifting only one end of the axle. A shackle two inches longer than stock will give you one inch of lift.

2) Spring Sag
SEXterra is right. Sick and deranged, but right. Flexing negative and heavy loads will sag a spring. Shackles in and of themselves WILL NOT EVER SAG A SPRING!

3) Articulation and AALs
Just adding a leaf to a spring pack will decrease articulation because you have made your pack stiffer. See item #1.

There is NO correlation between lift and articulation. Most lift spring are stiffer and actually hurt flex.

Just about everyone I've talked to with only the Shackle lift, wish they had gotten the AAL's instead. I recently installed the Roncho AAL's matched with a pair of Rancho 9000 shocks. The ride is MUCH better than stock. It's smoother, and bumps, potholes, etc.. are much easier on the X now. My stock suspension really wasn't that worn either..my X is still less than 6 months old.

Hope that helps,

Rich

Ok so how bout the torsion bar question do all kits offer the same sway away torsion bars.