This 4" long shackle can be used with the X7 style bearing carriers. Anodized black.
We have shackles 2", 2-1/2", 3", 3-1/2" and 4". A 1" or 1-1/4" difference in length between the left rear and the right rear is needed for proper arm angle. On the X4 and X6 style bearing carriers the right rear is typically just a female and male rod end threaded together making a 3-1/4" center to center shackle and the left rear uses a 2" shackle making a 4" center to center shackle with the rod ends screwed in.
On the X7 style bearing carriers, longer shackles are needed. We recommend using a 3" (just the length of the shackle itself with no rods end in it) on the right rear and a 4" on the left rear. With these shackles, you will need to use the 04-400 Torsion Arm Standoff to get the arm angles correct and the axle height correct. The shackle would then get mounted in the middle hole of the X7 bearing carrier plate.
If you like to run your car a little higher, then use a 2-1/2" and a 3-1/2" shackle.
Purchase this piece with the corresponding rod ends and jam nuts (1) 71-CML7, (1) 71-CMR7, (1) 70-325 and (1) 70-326.
Front to back shackle angle has an effect on spring rate, a greater angle equates to less spring rate. The X7 shackles are longer allowing for greater front to back misalignment between the torsion arm and the bearing carrier with minimal angle change to the shackle. This reduction in angle equates to a more consistent handling chassis.