Iv'e been hearing more and more about broken valve springs in the stock LS based and LT based engines. So this has encouraged me to start offering a solution to the problem. Sure you could just replace it with more affordable OEM spring, but If it was my vehicle I would upgrade to the PAC springs. They can handle more lift and a more agressive cam then stock While maintaining the stock behive spring profile. This means they should be just as if not more reliable than having OEM springs installed. It will increase valvetrain stability especially when upgrading to my performance pushrods. See spring specs below.
 
Brand:
PAC Racing Springs
Manufacturer's Part Number:
PAC-1219-16
Product Line:
PAC Racing 1200 Series Valve Springs
Valve Spring Style:
Beehive
Maximum Valve Lift (in.):
0.625 in.
Retainers Included:
No
Outside Diameter of Outer Spring (in.):
1.307 in.
Coil Bind Height (in.):
1.100 in.
Damper Spring Included:
No
Spring Rate (lbs/in.):
340 lbs./in.
Inside Diameter of Outer Spring (in.):
0.650 in./0.885 in.
Locks Included:
No
Valve Stem Seals Included:
No
Valve Springs Coated:
No
Remanufactured:
No