QA1 GS401-11300C Front Pro Coil Single Adjustable Coilover Kit 11in. Spring 300 lb/in Aluminum

The QA1 GS401-11300C is a front Pro Coil single adjustable coilover shock kit designed for GM A, G, and X-Body muscle cars. Featuring a lightweight billet aluminum threaded shock body, this bolt-in kit delivers a compelling combination of ride height adjustability and tunable damping performance — without requiring modifications to your existing stock-mount configuration.

The kit includes an 11-inch coil spring rated at 300 lb/in with a large tapered flat end, paired with a single adjustable shock offering 18 valving positions of simultaneous compression and rebound adjustment. The compressed length is 10.13 inches and the extended length is 14 inches, providing excellent suspension travel for both street and performance driving.

Key Features:

• Single adjustable valving with 18 simultaneous compression and rebound settings
• Up to 2 inches of ride height adjustability via the threaded aluminum shock body
• Includes 11-inch high-travel coil spring at 300 lb/in rating with large tapered flat end
• Compressed length: 10.13 in. | Extended length: 14 in.
• Lightweight billet aluminum construction reduces unsprung weight
• Bolt-in installation compatible with OE stamped steel or QA1 tubular control arms
• 100% dyno tested and serialized from the factory
• Serviceable and rebuildable by QA1 Authorized Service Centers
• Made in the USA (Lakeville, Minnesota)
• Backed by QA1's Limited Lifetime Warranty (registration required)

The Pro Coil spring design uses a smaller wire diameter and fewer coils than standard springs, resulting in more usable travel and reduced unsprung mass for quicker suspension response. Compatible accessory items include spanner wrenches (P/N T114W or T115W, required) and optional thrust bearing kit (P/N 7888-109).