Viper parts numbering system is as follows…(We’ll use part number 3x14x450 as our example.)1. The first number shows the inner diameter size. (3 denotes a 3” inner diameter spring, 2.5 denotes a 2.5" inner diameter spring)2. The second set of numbers shows the springs free length. (14 denotes a 14” long spring)3. The third set of numbers denotes the spring rate in pounds. (450 denotes a 450 lb per inch spring rate)
So our example of a 3x14x450 is a 14” long spring with a spring rate of 450lb and an ID of 3”.
We typically recommend using a lower (Main) spring that is 2" longer than the shocks travel length, and an upper (Tender) spring that is 2" shorter than the shocks travel length. (ie. A 12" travel shock will use a 14" Main spring and a 10" Tender spring) If the spring rates you need are not available using the longer lower/shorter upper method, you can use 2 equal length springs as needed. (ie. A 12” travel shock can use 2 12” springs)*****PLEASE NOTE--- 2.5 springs are for use on a 2.0 shock, 3.0 springs are for use on a 2.5 shock.*****
Be sure to use our Spring Rate calculator to help in deciding what springs to use for your application.