QA1 GD507-09550D Pro-Coil Double Adjustable Front Coilover Shock Kit 550 lb/in

The QA1 GD507-09550D Pro-Coil Double Adjustable Front Coilover Shock Kit delivers serious suspension performance for GM muscle cars and classic vehicles. Built around lightweight billet aluminum shock bodies, this bolt-in front coilover system combines fully independent compression and rebound damping adjustability with ride height tuning — all in one complete kit.

Double Adjustable Damping: The Pro-Coil D-Adj shock features two independent adjustment knobs — one for compression and one for rebound — each with 18 positions of adjustment. That's over 300 possible damping combinations per shock, giving you precise control whether you're tuning for street driving, autocross, or road racing.

Ride Height Adjustability: The fully threaded aluminum shock body allows 0 to –2 inches of ride height adjustment via a simple turn of the spring seat nut, making it easy to achieve the perfect stance or fine-tune corner weights for handling balance.

High-Travel Spring Included: The kit includes a 9-inch spring rated at 550 lb/in, specially engineered with fewer coils and a smaller wire diameter than conventional springs of the same rate. This design increases usable travel, reduces unsprung weight, and allows the damper to respond faster for optimized suspension performance.

Key Specifications:

• Shock Type: Double Adjustable (independent compression and rebound)
• Shock Body: Lightweight billet aluminum
• Compressed Length: 9.63 inches
• Extended Length: 14.5 inches
• Spring Length: 9 inches
• Spring Rate: 550 lb/in
• Spring Diameter: 2.5 inches
• Ride Height Adjustment Range: 0 to –2 inches
• Adjustment Positions: 18 per knob (300+ combinations)

Key Features:

• Lightweight billet aluminum coilover shock body
• 100% dyno tested and serialized
• Serviceable and rebuildable by QA1 Authorized Service Centers
• Easy bolt-in installation — no cutting or welding required
• Made in the USA
• Suitable for drag racing, street performance, autocross, road racing, and street rod applications
• Sold as a complete kit

QA1's Pro-Coil system is 100% dyno tested and fully rebuildable, making it a long-term performance investment. The kit installs with standard hand tools and is backed by QA1's one-year warranty against defects in material and workmanship.