This is the axle under kit (stock configuration) CLV-3300 being installed on Belltech lowering springs 5950. The spring eye diameter is smaller than stock being equal to the stock shackle bushing diameter. The aluminum bushing included in the Caltracks kit must be "turned down" to about 1.5 inches to fit in the Belltech springs.
CALTRACKS:
https://www.summitracing.com/parts/clv-3300