This is a full set of 24 titanium retainers and 82# valve springs for your LF3 or LF4 3.6 twin turbo which comes in the ATS-V, CTS/XTS V-Sport, and CT4 Blackwing. The factory valve springs can start to float at around 6000rpm when you turn up the boost. These valve springs will safely add around 1000 more RPMs to your power band. It is hard on valve springs and valves when they float (they can break and drop a valve into the cylinder), so these valve springs will not only improve performance, but also the reliability of your car. Are there higher # valve springs out there, of course some venders promote higher # being better, but you only need what you need, more is just more wear and tear on your timing chain assembly, valves, and valve seats.
For ease of installation we highly recommend our ZZP Cam Sprocket tool, found here.
The stock valve springs are 58#