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. Base Shock: The DSE/JRI 'Detroit Tuned' base shock is a 'pure blood pedigree' racing shock in its most efficient form as a non-adjustable unit. Although non-adjustable, it shares all the increased dynamic responses of all the JRI adjustable models while providing excellent ride quality on the street. Spring Rate: 650lbs/in Spring Free Length: 9.5in