High misalignment spacers are designed for suspension joints, steering tie rod ends and anything else that uses the pivot of a spherical bearing such as heim joints, rod ends and uniballs. They have two functions. They reduce the hole size to accommodate a smaller bolt and increase the max angle of a spherical bearing.
How much the angle is increased is determined by the bolt size and the amount of material removed. When more material is removed, the strength of the spacer is decreased. The same happens when using a larger bolt. To compensate for this we only use heat treated 17-4 stainless steel for our spacers. This also prevents corrosion when used in everyday applications.
Stack height or stack width, depending on which way you look at it, is an important dimension for you to know for the length of the bolt you'll need plus the gap that you'll need in order to put the rod end or uniball on your vehicle.
We sell the spacers individually because occasionally customers will use two different heights of spacers on one rod end or uniball to achieve the stack height required for their vehicle.