QA1 GS401-10650B GM Pro-Coil Front Coilover System Single Adjustable 650 lb/in

The QA1 GS401-10650B GM Pro-Coil Front Coilover Conversion System delivers a bolt-in upgrade from factory suspension to a fully adjustable coilover setup. Designed for stock-mount front coilover applications on GM vehicles, this single-adjustable system provides precise control over both ride height and valving to suit a wide range of driving styles — from street performance and autocross to drag racing and road racing.

At the heart of this kit are two GS401 single-adjustable, lightweight billet aluminum coilover shocks featuring a fully threaded body, giving you a 3-inch ride height adjustment range so you can dial in the perfect stance or fine-tune front-end weight balance. Each shock is 100% dyno tested and serialized at the factory, and can be serviced or rebuilt through QA1 Authorized Service Centers.

Paired with the shocks are two specially designed 10-inch high-travel tapered flat-end springs rated at 650 lbs./in. (part# 10HTSF650). These American-made springs feature fewer coils and a reduced wire diameter compared to standard springs, which maximizes coil travel and compliance across a broad range of conditions. The shock compressed length is 10.13 inches with an extended length of 14 inches, and the spring free length is 11 inches. This kit is suited for vehicles with a front-end weight of approximately 2,201–2,300 lbs.

Kit Includes:

• 2x QA1 GS401 single-adjustable billet aluminum coilover shocks
• 2x 10HTSF650 tapered flat-end high-travel springs (650 lbs./in.)
• All necessary mounting hardware

Key Features:

• Single-adjustable simultaneous compression and rebound valving
• Lightweight billet aluminum shock body construction
• Fully threaded body with 3-inch ride height adjustment range
• 10.13 in. compressed / 14 in. extended shock length
• 650 lbs./in. spring rate — tapered flat upper end style
• 100% dyno tested and individually serialized
• Serviceable and rebuildable by QA1 Authorized Service Centers
• Made in the USA
• Sold as a pair

Suitable for drag racing, street performance, autocross, road racing, and street rod applications. This system installs using the factory shock mount locations for a straightforward, no-cut installation.