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90# Valve Springs
Item #: GM-12499224
Availability: In Stock
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Safely increasing cam lift or maximum engine RPM can require new valve springs. On the 3800 we use LS1 behive valve springs which means that when running new springs you will also need LS1 retainers.
90# springs are GM LS6 springs*. The LS6 comes from the factory with .550" of lift and spins to 6500 RPM to give an idea of what the springs were made for. Seat pressure is lower than the Comp Cams 105# springs but spring rate is higher so they do work well for aggressive ramp rates. There springs work well with the VS and NIC cams when shifting at 6000 rpm. Because of the higher spring rate, timing chain dampener life is lower than with the 105's. 1.80 recommended install height.
Why install valve springs?
When boost is increased, that boost is pushing on the back side of the intake valves, therefore your valve spring pressure is reduced. So when you add valvesprings 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, then we would recommend the Crow Cams 140# or PAC 150# valve springs instead.
*Some users have reported that in naturally aspirated applications the LS6 springs have excessive noise and cause false KR readings at certain rpm points. We have not confirmed this.
These are all packaged in sets of 12.
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