QA1 RCK52366 Rear Coilover Kit Big Wheel Single Adj 1978-1988 GM G-Body 200 lb

Vehicle Fitment

• 1978-1988 Chevrolet Malibu (GM G-Body)
• 1978-1988 Chevrolet Monte Carlo (GM G-Body)
• 1978-1987 Chevrolet El Camino (GM G-Body)
• 1978-1988 Buick Regal (GM G-Body)
• 1978-1988 Oldsmobile Cutlass Supreme / Cutlass Calais (GM G-Body)
• 1978-1988 Pontiac Grand Prix (GM G-Body)
• 1978-1981 Pontiac LeMans (GM G-Body)
• 1978-1981 Pontiac Bonneville (GM G-Body)

Fitment Notes

• Bolt-in installation for factory rear end housings - no cutting or welding required
• Aftermarket rear end housings require QA1 weld-on lower coilover bracket 9037-1081 (sold separately)
• Big Wheel Kit - bracket geometry provides clearance for up to 24-inch wheels
• Ride height adjustability: up to 1 inch higher than stock to 3 inches lower than stock
• 200 lbs/in spring rate - suited for average-weight G-Body street builds; contact QA1 tech support at 952.985.5675 for spring rate guidance; alternate spring rates available separately
• For the double adjustable version of this kit see QA1 RCK52367
• Register shocks at QA1 before installation to activate Limited Lifetime Warranty

Features

• Complete bolt-in rear coilover conversion kit with Big Wheel bracket geometry - specially engineered mounting brackets clear up to 24-inch wheels while providing up to 3 inches of rear drop
• Single adjustable Proma Star coilovers - 18 positions of simultaneous compression and rebound adjustment for easy on-car ride quality tuning between comfort and performance
• Fully threaded aluminum shock bodies and adjustable brackets allow ride height adjustment from 1 inch above stock down to 3 inches below stock
• High travel 200 lbs/in springs (12-inch, 2.5" ID) - engineered for G-Body rear suspension geometry with reduced unsprung weight for improved suspension response
• Vehicle-specific mounting brackets engineered for 1978-1988 GM G-Body geometry - bolt-in to factory rear end housings without cutting, welding, or custom fabrication
• Eyelet upper and lower shock mounts for secure, articulating fitment
• Lightweight aluminum shock body - silver anodized for durability and corrosion resistance
• 100% dyno-tested and serialized for verified, consistent performance
• Serviceable and rebuildable by QA1 Authorized Service Centers
• Made in the USA at QA1's Lakeville, Minnesota facility

Specifications

• Part Number: RCK52366
• Type: Rear Pro Coil Bolt-In Coilover Conversion Kit - Big Wheel, Single Adjustable
• Application: 1978-1988 GM G-Body (Malibu, Monte Carlo, El Camino, Regal, Cutlass, Grand Prix)
• Shock Type: Proma Star Single Adjustable Coilover
• Valving: 18 positions (simultaneous compression and rebound)
• Spring Rate: 200 lbs/in
• Spring Length: 12 inches
• Spring ID: 2.5 inches
• Ride Height Range: +1 inch (above stock) to -3 inches (below stock)
• Max Wheel Diameter Clearance: 24 inches
• Upper Mount: Eyelet
• Lower Mount: Eyelet
• Shock Body Material: Aluminum, silver anodized
• Internal Design: Twin-tube
• Factory Housing Compatibility: Bolt-in (no welding)
• Aftermarket Housing Compatibility: Requires QA1 9037-1081 weld-on bracket (sold separately)
• Welding Required: No (factory housing); Yes (aftermarket housing)
• Warranty: Limited Lifetime (register before installation)
• Quantity: Kit (2 shocks, 2 springs, mounting brackets, hardware)
• Made in the USA

Included Components

• 2x Proma Star Single Adjustable Coilover Shocks - Aluminum, Silver Anodized (100% Dyno-Tested and Serialized)
• 2x High Travel Coilover Springs - 200 lbs/in, 12-inch, 2.5" ID
• 2x Vehicle-Specific Big Wheel Rear Mounting Bracket Sets (upper and lower)
• 1x Complete Hardware Kit (all required mounting hardware)

Product Description

The QA1 RCK52366 is a bolt-in rear Pro Coil Big Wheel coilover conversion kit engineered for 1978-1988 GM G-Body vehicles - including the Monte Carlo, Malibu, El Camino, Regal, Cutlass, and Grand Prix. The "Big Wheel" designation refers to bracket geometry that provides clearance for up to 24-inch wheels, making this kit the go-to choice for G-Body builds running large-diameter wheel fitments. The single adjustable Proma Star coilovers deliver 18 simultaneous compression and rebound valving positions alongside a ride height adjustment range of 1 inch above stock to 3 inches below stock via the fully threaded shock body and adjustable mounting brackets.

The kit installs bolt-in to factory GM G-Body rear end housings without cutting or welding. Aftermarket rear end housings require QA1's weld-on lower coilover bracket 9037-1081, sold separately. The 200 lbs/in spring rate is suited for average-weight G-Body street builds; alternate spring rates are available from QA1 for drag, autocross, or heavier applications. For independent compression and rebound control, the double adjustable version RCK52367 is also available. Register shocks at QA1 before installation to activate the Limited Lifetime Warranty.