Description: The PAC-1218 Spring Kit is a drop-in high performance spring kit for all OE LS cylinder heads and is rated for up to .600" lift. This spring kit uses all same hardware, including seats, retainers, and locks and is drop-in. The PAC-1218s are an ovate beehive spring that has increased loads, rates and frequencies for more aggressive cams. If you want to upgrade your engine, get more horsepower, this valve spring set is your need. Package includes 16 springs. Specification: Material: Steel Quantity: 16Pcs Manufacturer Part Number: PAC-1218 Superseded Part Number: PAC1218 Other Part Number: PAC-1218-16 Outside Diameter of Outer Spring (in): 1.290 in. Height: 1.14in. Install Load: 130lbs Install Height: 1.8" Open Height: 1.175" Open Load: 318 lbs Spring Rate: 313 lbs./in. Inside Diameter of Outer Spring: 0.885 in. Valve Spring Style: Beehive Size Chart: Package Size: 39x19x7.3cm/15.35x7.48x2.87inch Package Includes: 16 Pieces PAC Racing Springs Note: 1. Please allow slightly error due to manual measurement. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. 3. Wish you a wonderful on-line shopping