QA1 GD401-10550C GM Front Pro Coil Double Adjustable Coilover Shock Kit 10in 550lb/in

The QA1 GD401-10550C GM Pro Coil Double Adjustable Front Coilover Shock Kit is a premium bolt-in suspension upgrade engineered for muscle car owners seeking dialed-in ride height, superior valving control, and versatile performance from street to track. The kit ships as a pair and features lightweight billet aluminum coilover shocks paired with a 10-inch, 550 lb/in high-travel coil spring with a large tapered flat end.

The double adjustable design delivers truly independent compression and rebound tuning, with 18 positions of rebound and 18 positions of compression on separate knobs — providing 324 unique valving combinations for precise suspension tuning. A fully threaded shock body allows up to 2 inches of ride height adjustment with a simple turn of the spring seat nut, making stance changes fast and repeatable.

Key Features:

• Shock Lengths: 8.63" compressed / 12.88" extended
• Spring: 10-inch length, 550 lb/in rate, large tapered flat end
• Construction: Lightweight billet aluminum shock body
• Adjustability: Independent compression and rebound — 18 positions each (324 total valving options)
• Ride Height: Up to 2 inches of lowering adjustment via spring seat nut
• Installation: Easy bolt-in fitment compatible with OE stamped steel or QA1 tubular control arms
• 100% dyno tested and serialized at the factory
• Serviceable and rebuildable by QA1 Authorized Service Centers
• Suitable for drag racing, street performance, autocross, road racing, and street rod builds
• Made in the USA — manufactured in Lakeville, Minnesota
• Sold as a pair

QA1's high-travel coil springs are purpose-built for the Pro Coil system, featuring fewer coils and a smaller wire diameter compared to standard springs of the same rate and length. This design increases usable travel, reduces unsprung weight, and allows the suspension to react faster for optimized handling performance. The springs have been successfully tested across applications ranging from daily street driving to hard-core racing.

Included Accessories:

• 2 x QA1 double adjustable billet aluminum coilover shocks
• 2 x 10-inch, 550 lb/in high-travel coil springs (large tapered flat end)
• All necessary hardware

Optional Accessories (sold separately): Spanner Wrench P/N T114W or T115W (required for installation); Thrust Bearing Kit P/N 7888-109 (optional, simplifies ride height adjustments). QA1 Double Adjustable Pro Coil Kits are covered by a Limited Lifetime Warranty when registered at QA1.net.