Safely increasing cam lift or maximum engine RPM will require new valve springs. For example on the 3800 we use LS1 "beehive" valve springs which means that when running new springs you will also need our ZZP retainers.
Why install valve springs?
When boost is increased, that boost is pushing on the back side of the intake valves, therefore your actual valve spring pressure is reduced. So when you add valve springs it allows you to rev higher and increase your boost without losing any performance to valve float. If you are boosted and want to shift above 6000rpms these springs will be a perfect solution for you.
1.80 recommended install height.
These are all packaged in sets of 12.