QA1 R231-200 Rear Coilover Conversion System GM C10 Double Adjustable 200 lb/in Springs

The QA1 R231-200 is a complete bolt-in rear coilover conversion system engineered specifically for 1973–1987 GM C10 Squarebody trucks equipped with a GM 12-bolt rear differential. This all-inclusive kit replaces the factory leaf spring setup with a modern torque arm-based coilover system, delivering dramatically improved stance, ride quality, and handling — all without cutting, welding, or removing the truck bed.

At the heart of this system is QA1's unique bolt-in torque arm design, which connects the rear axle to a forward chassis mount to manage axle rotation and drivetrain forces. By isolating these forces from suspension movement, the springs and shocks can operate more effectively, resulting in a planted, predictable ride under all driving conditions.

Key Features:

• Double adjustable shocks — independent tuning of compression and rebound for precise ride quality and handling control
• 200 lb/in spring rate (Medium) — ideal for street-driven builds seeking a balance of comfort and performance
• 4" to 7" of rear drop below stock ride height, fully adjustable via the coilover system
• GM 12-bolt housing compatible — designed specifically for trucks with the GM 12-bolt rear differential
• Bolt-in installation — no cutting, welding, or bed removal required
• Black powder-coat finish on steel components for corrosion resistance and a clean appearance
• Complete kit — includes crossmember, panhard bar, shocks, springs, torque arms, trailing arms, and all necessary hardware

The R231-200 eliminates the guesswork of mixing individual components by delivering a fully engineered rear suspension package where every part is designed to work in harmony. For maximum adjustability across all four corners, this rear system pairs directly with QA1's front suspension kit. A one-year limited warranty against defects in materials and workmanship is included.