We have been making this for ourselves for years and decided we should share them with other fabircators! 
These are made from 17-4 stainless and are available in 2 bolt sizes and oversized .030" to account for weld shrinkage! 
We have tried many types of materials and stainless by far out lasts steel and alauminum as they tend to wear down from being used and removed after welding. 
 
- 1.25" outer diammeter to ensure both sides of work peice stay true
- Available in 1/2" and 5/8" both sizes 
- 1.53" spread for 1.5" shock spacer stacks (.030 oversized for welding)
- Spacer size is laser engraved on the side to make it easy to find the right size!
- Sold individually*
 
These are a must have for any off road fabricator and shop!