To make a long story short I bought an LS1 out of a 2000 corvette with around 30k miles.. I was tearing into the heads before I clean them up and noticed that it had dual valve springs ... I'm pretty sure these are not stock is there any way to ID them to tell what they are and how much lift? Here are some pics

 

The retainer appears to be a Crane retainer. I am guessing the spring is as well.

 

Thanks! They seem to be in excellent shape. Im just trying to find out max lift on them.. i would assume atleast .600 lift .. i plan on reusing them..

 

They will hold .600 easy.