Our exclusive Detroit Speed A-Body Speed Kits are designed to work as an integrated system on your vehicle. By utilizing our proven Detroit Speed components and carefully selecting components designed to complement each other, each speed kit is for your driving needs with the ease of a bolt-on package. Speed Kit 1 is designed to bring your classic GM muscle car into the 21st century with improvements in ride, handling, and camber/caster correction. Speed Kit 3 takes performance to the next level with coilover shocks and springs that provide ride height adjustment. Single Adjustable Shock: Includes all features of base shock with 'Detroit Tuned' valving plus installed rebound adjustment with the simple turn of a knob while providing excellent ride quality on the street. Spring Rate: 650lbs/in Spring Free Length: 9.5in