QA1 RCK52381 Rear Pro-Coil Coilover Conversion Kit GM B-Body Double Adjustable 300lb Springs

The QA1 RCK52381 Rear Pro-Coil Shock System is a complete bolt-in coilover conversion kit designed for 1978–1996 GM B-Body full-size cars. This kit eliminates the factory rear coil spring setup and replaces it with a performance-tunable coilover system, giving you independent control over ride height and suspension valving without cutting or welding.

At the heart of the kit are QA1's double adjustable aluminum shocks, which provide 18 positions of independent compression and rebound adjustment. This allows precise tuning across a wide range of driving conditions — from daily street use to aggressive track applications. The shocks feature a fully threaded body for easy ride height adjustment, letting you dial in the perfect stance or fine-tune corner weights for improved handling balance.

The included 12-inch, 300 lb/in high-travel springs are engineered specifically for QA1's Pro-Coil system. Their lightweight design features fewer coils and a smaller wire diameter, increasing coil travel and reducing unsprung weight for faster suspension response.

Kit Includes:

• 2 double adjustable aluminum coilover shocks
• 2 high-travel 12-inch, 300 lb/in springs
• Specially designed USA-made mounting brackets
• All necessary hardware for a complete bolt-in installation

Key Features:

• Bolt-in installation — no cutting or welding required
• 18-position independent compression and rebound adjustment
• Fully threaded shock body for ride height adjustability
• Lightweight aluminum shock construction reduces unsprung weight
• 100% dyno tested and serialized at the factory
• Rebuildable and revalveable for long-term serviceability
• Proudly made in the USA in Lakeville, Minnesota
• Limited Lifetime Warranty on shocks (registration required at QA1.net/Warranty)
• Lower shock mount bracket may not be compatible with aftermarket rear end housings

QA1's Pro-Coil rear coilover system is a proven upgrade for GM B-Body enthusiasts looking to transform their suspension from stock to fully tunable performance. The RCK52381 is sold as a complete pair and is compatible with both street and race applications.