QA1 GD507-11300C GM Pro-Coil Front Coilover Kit Double Adjustable 300 lb/in Spring

The QA1 GD507-11300C is a front Pro-Coil double adjustable coilover conversion kit engineered for GM full-size vehicles. This complete kit pairs QA1's lightweight billet aluminum GD507 shock body with an 11-inch, 300 lb/in tapered flat large-style spring, delivering a bolt-in upgrade to fully adjustable coilover suspension using the factory stock mounting locations.

The double adjustable shock body features independent compression and rebound adjustment knobs, each offering 18 positions of tuning — resulting in 324 unique valving combinations. The fully threaded aluminum body allows up to 2 inches of ride height adjustment, letting you dial in the perfect stance or fine-tune weight balance for improved handling. Compressed length is 9.63 inches and extended length is 14.50 inches. Upper mount is stud type; lower mount is 3.5-inch T-bar type.

Key Features:

• Front Pro-Coil double adjustable coilover shock kit — sold in pairs
• Lightweight billet aluminum shock body for reduced unsprung weight
• Independent compression and rebound adjustment — 18 positions each (324 valving combinations)
• Fully threaded body for ride height adjustment up to 2 inches
• Includes 11-inch high-travel springs rated at 300 lb/in — tapered, flat top, large diameter style
• Compressed length: 9.63 in. | Extended length: 14.50 in.
• Stud-type upper mount | 3.5-inch T-bar lower mount — stock location fitment
• 100% dyno tested and serialized at the factory
• Serviceable and rebuildable by QA1 Authorized Service Centers
• Made in the USA
• Suited for street performance, drag racing, autocross, road racing, and street rod use

QA1's Pro-Coil high-travel springs are American-made with fewer coils and a smaller wire diameter than conventional springs, providing greater coil separation and increased suspension travel. This design reduces unsprung weight and improves suspension response across a wide range of driving conditions, from daily street use to competitive motorsport applications.