BTRs .560" lift LS6-style valve springs give you all of the performance of the venerable OEM LS6 valve spring (GM part # 12499224 or 12586484) at a fraction of the cost. These springs pair perfectly with truck series camshafts and are also a great option for replacing worn out or broken springs in stock applications. 100 lbs @ 1.800” 285 lbs @ 1.240” Coil bind @ 1.150”