I bought this item because I needed to convert standard shocks into custom build coilovers. Like many others, I had trouble finding SPECs for this product. So here. Large Spring (Front): 3.575" OD, 2.620" ID, 6.375" Length, 0.480" Wire OD, 1" Compression Spring Rate, 450-500#. Small spring (rear): 3.400" OD, 2.600" ID, 6.160" long, 0.400 wire diameter, 1" 250# compression ratio. Adjusting sleeve: 2.275" OD, 2.027 ID, length 4.730" thread length 3.835" used by Acme) has a 1mm clearanceβ¦