Competition Engineering's rear coil-over springs are a great choice for drag race, Pro Street, street rod, and kit cars. The springs are manufactured on CNC equipment for accurate compression rates from one spring to another. Made of premium-grade chrome silicon steel, these durable springs will remain true to size and weight, launch after launch. Each spring is designed for specific rear-end weight to ensure proper ride height and suspension travel, and powdercoated for extended spring life.