QA1 RCK52444 Rear Pro-Coil MOD Series Coilover Conversion Kit, 12in. 170 lb/in Springs

The QA1 RCK52444 is a bolt-in rear coilover conversion kit engineered for 1973–1977 GM A-Body vehicles. Featuring QA1's top-of-the-line MOD Series shocks, this kit delivers an unmatched level of tunability for high-performance street driving, pro-touring, and drag race applications — all without cutting or welding.

At the core of this kit is QA1's proprietary QuickTune Technology, which uses dry modular valve packs that can be swapped out in minutes while the shock remains on the vehicle. Unlike conventional shocks, the MOD Series can be revalved without interrupting the oil path or exposing the internals to debris or air contamination. The unique double-adjustable design provides independent control over compression and rebound characteristics via an adjustable low-speed bleed, giving you an expansive force curve and an unprecedented range of tuning options.

Key Features:

• MOD Series double-adjustable shock absorbers with QuickTune Technology for rapid revalving on the car
• Dry modular valve packs — swappable without removing the shock or opening the oil circuit
• Nitrogen-charged canister available in piggyback or remote configuration for installation flexibility in tight spaces
• Indexable base eyelet allows the shock and canister to be repositioned for optimal placement
• Fully threaded aluminum shock body for precise ride height adjustment
• Includes two (2) MOD Series shocks, two (2) 12-inch high-travel springs rated at 170 lb/in, all mounting brackets, and necessary hardware
• Bolt-in installation — no cutting or welding required
• 100% dyno tested and serialized at QA1's Lakeville, Minnesota facility
• Rebuildable and revalveable by QA1 or an authorized QA1 service center
• Proudly made in the USA

What's Included:

• 2x QA1 MOD Series rear shocks
• 2x 12-inch high-travel springs — 170 lb/in spring rate
• Specially designed mounting brackets
• All necessary installation hardware

QA1's American-made high-travel springs feature fewer coils and a smaller wire diameter than standard springs, resulting in greater suspension travel and reduced unsprung weight for improved handling response. Medium compression and rebound valve packs are included as standard; soft and firm packs are also available separately to further tailor the shock's performance to your specific application.