A spring is a spring right? Wrong! When UMI chose to manufacture our own line of springs we went all out. Designed in conjunction with a leading Sprint Cup chassis engineer, these springs are the best in the business. Our front springs are wound from 5160 CrSi premium wire and feature a linear 530 lb/in rate. The rear springs are wound from 9254 CrSi premium wire and feature a linear 130 lb/in rate. The linear rate provides consistent handling characteristics which are important for Auto-x and Pro-Tour applications while the increase in stiffness reduces body roll and prevents the *floating* feeling so common with the A-body. These springs are suitable for Auto-x and Pro-Tour applications as well as corner carving/cruising. The ride height is engineered for a 2* lowering with standard SBC, Pontiac 400 and aluminum head/intake Big Block Chevy as well as LS power (lightened cars may require spring trimming). The front springs are also suitable for full weight Big Block applications when ?* nose down rake is desired. They have a tough, black powder coat finish and UMI proudly manufactures these premium quality springs in the USA.