These Global West coil springs are a straight rate 500 lbs. small block spring. They will lower the car 1" from stock height, and can be used with any lower control arm that excepts standard type coil springs. These springs are designed for Performance street applications. The stock springs have a spring rate is only 325 pounds per inch. While you might think 500 is stiff, the actual racing rate is a lot higher for this application. A 500 pound is spring is perfect for street performance.