QA1 RCK52389 Rear Pro-Coil Double Adjustable Coilover Conversion Kit 170 lb/in Springs

The QA1 RCK52389 is a bolt-in rear coilover conversion kit designed for 1965–1970 Chevrolet B-Body muscle cars. This complete Pro-Coil system replaces the factory rear suspension with a fully adjustable coilover setup, delivering precise ride height control and tunable damping performance for street and track use.

Featuring double adjustable aluminum shocks, this kit provides 18 independent positions of compression adjustment and 18 positions of rebound adjustment, yielding up to 324 unique valving combinations for dialing in the exact suspension feel you want. The fully threaded shock body allows ride height fine-tuning to achieve the perfect stance or optimize weight balance for handling.

The included American-made high-travel springs are specially engineered for QA1's Pro Coil systems. Their reduced coil count and smaller wire diameter create greater distance between coils, maximizing suspension travel, reducing unsprung weight, and improving suspension response.

Kit Contents:

• 2 double adjustable aluminum coilover shocks (100% dyno tested and serialized)
• 2 high-travel springs — 170 lb/in spring rate, 12 in. length
• All USA-made mounting brackets and necessary hardware

Key Features:

• Bolt-in installation — no cutting or welding required
• Fully threaded shock body for ride height adjustability
• Double adjustable: 18-position compression + 18-position rebound (324 combinations)
• Rebuildable and revalveable at QA1 factory or authorized service centers
• 100% dyno tested and serialized at the factory
• Proudly made in the U.S.A. in Lakeville, Minnesota

The RCK52389 is backed by QA1's limited warranty. Shocks are eligible for registration at QA1.net/Warranty. Multiple spring rate options are available for this application to suit driving styles ranging from street cruising to performance track use.