Fits 1967-1969 Chevrolet Camaro (Base, RS, SS, Z28) and Pontiac Firebird (326, 350, 400, HO, Sprint, Trans Am).

Ditch the restrictive factory leaf springs and modernize your 1967-1969 GM F-Body rear suspension with the QA1 triangulated 4-link system. This comprehensive upgrade replaces the leaf spring architecture with a tubular 4-link and double adjustable coilovers, significantly improving geometry, ride quality, and traction. The system is designed to work with both standard wheel wells and mini-tubs, providing clearance for up to 11-inch wide wheels on 1967-1968 models and 12-inch wide wheels with 335 tires on 1969 models.

The included double adjustable shocks feature independent knobs for compression and rebound tuning, allowing you to dial in performance for the street or the track without removing the links. This kit offers a ride height adjustment range from +2 inches to -3 inches relative to stock, enabling the perfect stance while maintaining suspension travel.

• Ride Height Adjustability: +2" to -3" adjustment range for precise stance control.
• Double Adjustable Valving: Independent compression and rebound knobs for 18+ positions of tuning.
• Tire Clearance: Optimized for wider wheel packages; fits up to 12" wide wheels (requires mini-tubs).
• Installation: Requires welding to the axle housing; no floor pan modifications necessary.
• Included Hardware: Spanner wrench and all necessary mounting hardware.
• Manufacturer Part Number: R256-170
• Origin: Made in the USA.

Fits select 1968-1970 Dodge Charger, Coronet, and Plymouth B-Body models including GTX, Road Runner, and Satellite.

The QA1 Rear 4-Link Suspension System (MPN: R253-175) converts your 1968-1970 Mopar B-Body from traditional leaf springs to a modern triangulated 4-link coil-over design. This system provides a more planted feel, allows for larger wheel and tire fitment, and corrects the wheelbase for improved geometry. The design specifically accommodates up to 3-inch bumper-exit exhaust systems for a clean finish.

Constructed with powder-coated tubular steel, the kit includes a heavy-duty crossmember along with upper and lower trailing arms. It is compatible with factory-located or inboard-located leaf spring mounts and supports popular rear ends, including the Mopar 8 3/4-inch, Ford 9-inch, and Dana 60. Double-adjustable coil-over shocks offer independent control over compression and rebound, making it an ideal choice for vehicles used for drag racing, autocross, or spirited road course driving.

• Triangulated 4-link design replaces factory leaf spring suspension
• Double-adjustable shocks for precision compression and rebound control
• Adjustable ride height for custom stance and performance tuning
• Powder-coated tubular steel components: crossmember, upper and lower trailing arms
• Compatible with Mopar 8 3/4", Ford 9", and Dana 60 axle housings
• Installation requires minor cutting and welding to the frame and axle housing
• Includes all necessary installation hardware
• Manufacturer Part Number: R253-175
• Made in the USA

Fits select 1973-1986 Chevrolet C10 Pickup and Suburban models equipped with a GM 10-bolt rear axle.

Transform the handling of your Square Body with the QA1 R230-250 Rear Suspension Conversion System. This engineered-from-scratch kit replaces the restrictive factory leaf springs with a modern torque arm design that eliminates the binding issues common in traditional 4-link setups. Designed for a straightforward installation, this system bolts directly to factory mounting points, allowing you to upgrade your rear suspension without removing the truck bed.

The system features double-adjustable coil-over shocks, providing independent control over compression and rebound to fine-tune your ride quality and launch characteristics. With a 250lbs/in spring rate and a firm valving profile, it offers superior stability and body control. The adjustable coil-over mounts allow for a significant drop of 4" to 7" below stock height, helping you achieve the perfect stance while maintaining suspension travel.

• MPN: R230-250
• Axle Compatibility: Fits GM 10-Bolt housings
• Adjustment Range: 4" to 7" drop below factory ride height
• Shock Type: Double adjustable coil-overs, 100% dyno tested and serialized
• Spring Rate: 250lbs/in
• Construction: Bolt-in torque arm design manufactured in Lakeville, Minnesota
• Installation: No bed removal required; includes all necessary mounting hardware

Fits 1963-1972 Chevrolet C10 Panel, Pickup, and Suburban models originally equipped with coil-spring rear suspension.

The QA1 Rear Suspension Conversion System transforms your C10's factory coil-spring rear end into a fully adjustable coilover setup. This bolt-on kit provides up to 6 inches of total drop, allowing you to achieve a custom stance while significantly improving handling. By relocating the coilovers to the outside of the frame rails, the system increases cornering stability and creates additional clearance for popular aftermarket rear-mounted fuel tanks.

This system features tubular steel truck arms with integrated pinion angle adjustment, eliminating the need for angled shims and allowing for precise wheelbase indexing. An adjustable panhard bar keeps the rear axle centered, while multiple mounting locations allow for roll center geometry correction based on your specific ride height. The entire system is designed for a straightforward installation that can be completed without removing the truck bed.

• Valving: Double Adjustable (Firm) for precise compression and rebound tuning
• Spring Rate: 250 lbs/in
• Drop Range: Up to 6 inches of total drop
• Geometry: Integrated pinion angle adjustment and adjustable panhard bar
• Construction: Heavy-duty tubular steel truck arms
• Installation: Bolt-on design; no bed removal required
• Origin: Made in the USA
• Manufacturer Part Number: R210-250

Fits 1963-1972 Chevrolet C10 Pickup, Panel, and Suburban models originally equipped with coil-spring rear suspensions.

The QA1 C10 rear suspension conversion system is engineered to replace factory coil springs with high-performance adjustable coil-overs, providing up to a 6-inch total drop. This system relocates the coil-overs to the outside of the frame rails, closer to the wheels, significantly improving cornering stability while creating additional clearance for popular aftermarket rear-mounted fuel tanks. The included tubular steel truck arms feature integrated pinion angle adjustment, allowing you to set the wheelbase and driveline geometry precisely without the use of angled shims.

Designed for a straightforward bolt-on installation, this kit can be installed without removing the truck bed. The adjustable panhard bar keeps the rear axle centered for predictable handling, and multiple mounting locations allow for roll center geometry correction based on your chosen ride height.

• Manufacturer Part Number: R210-200
• Shock Series: Double Adjustable for independent compression and rebound tuning
• Spring Rate: 200lbs/in (Medium)
• Ride Height: Adjustable up to 6" total drop
• Construction: High-strength tubular steel truck arms
• Installation: Direct bolt-on design; no bed removal required
• Origin: Made in the USA

Fits 1970-1981 Chevrolet Camaro and Pontiac Firebird models. This QA1 rear four-link suspension system replaces restrictive factory leaf springs with a modern triangulated 4-link configuration, providing superior axle control and a fully adjustable ride height for the second-generation GM F-Body.

Constructed with tubular steel links and featuring single-adjustable Proma Star coilover shocks, this kit allows you to fine-tune dampening and dial in the perfect stance. The design provides significantly more clearance than factory setups, accommodating wheels up to 12 inches wide and 335-series tires when used with mini-tubs. By relocating the suspension pick-up points, it optimizes roll center and center of gravity for improved cornering stability and traction without sacrificing street drivability.

• Manufacturer Part Number: R157-170
• Adjustable ride height: Typical range 10.75" to 12" (Camaro) / 13.75" to 15" (Firebird) from axle centerline to fender arch
• Single-adjustable Proma Star shocks for simultaneous compression and rebound tuning
• Includes spanner wrench for easy coilover height adjustment
• Supports both standard and mini-tubbed wheel wells
• Requires welding for installation
• Requires exhaust modification (will not clear over-the-axle exhaust systems)
• QA1 subframe connectors strongly recommended for chassis rigidity
• Made in the USA

Fits 1988-1998 Chevrolet C1500 2WD pickups across all submodels including 454 SS, Base, Cheyenne, Scottsdale, Silverado, and WT.

The QA1 Rear Suspension Conversion System modernizes the handling and stance of your GMT400 C1500 without the need to remove the truck bed. Engineered as a high-performance alternative to traditional 4-link setups, this system provides a 4-inch to 7-inch drop while eliminating the binding issues common in other designs. The torque arm and panhard bar configuration offers superior control over axle movement, allowing you to dial in a precise stance and a smooth, compliant ride.

This "Soft" spring rate configuration features 170lbs/in springs and single-adjustable shocks, allowing you to tune the rebound damping to your specific driving preference. The system is entirely bolt-in, requiring no welding for installation. Every component, from the bracket mounts to the trailing arms, is designed to be adjustable independently so that one change does not negatively impact another setting.

• MPN: R140-170
• Spring Rate: 170 lbs/in (Soft)
• Adjustability: Single-adjustable shock valving (rebound)
• Drop Range: 4" to 7" below factory ride height
• Installation: 100% bolt-on; no welding or bed removal required
• Construction: Proudly manufactured in Lakeville, Minnesota
• Testing: All shocks are 100% dyno tested and serialized
• Hardware: Includes all necessary mounting hardware, panhard bar, torque arm, and trailing arms

Fits select 1973-1986 Chevrolet C10 and C10 Suburban models (including Big Ten, Cheyenne, Custom, Scottsdale, and Silverado). This QA1 rear suspension conversion system transforms your vintage pickup's utility-focused leaf spring setup into a high-performance, modern handling machine without requiring you to remove the truck bed during installation.

Engineered from the ground up, this system features a unique bolt-in torque arm design. Unlike traditional 4-link setups that can suffer from binding, the QA1 torque arm maximizes axle control and eliminates bind, resulting in a significantly smoother ride and more predictable cornering. The included single-adjustable coil-over shocks allow you to fine-tune the damping with 18 simultaneous compression and rebound settings, paired with 170lbs/in soft-rate springs for a street-friendly feel.

Achieve the perfect stance with integrated ride height adjustability, offering a range from 4 inches to 7 inches below the factory stock level. All components are manufactured in QA1's Lakeville, Minnesota facility, featuring 100% dyno-tested and serialized shocks for verified performance.

• Replaces factory leaf springs with a high-performance torque arm system
• Allows for 4-7" drop from stock ride height
• Includes single-adjustable coil-overs for precision valving control
• Soft-rate 170lbs/in springs for optimized ride quality
• Compatible with GM 10-bolt rear axles
• Full bolt-in installation with no bed removal required
• Made in the USA and includes all necessary mounting hardware
• Manufacturer Part Number: R130-170

Fits 1965-1972 Ford F-100 Base models.

Transform the handling and stance of your classic truck with the QA1 R120-200 Rear Coil-Over Conversion System. This bolt-in kit replaces the factory leaf spring suspension with a high-performance torque arm design, specifically engineered to eliminate binding and provide a smooth, controlled ride. This system allows for a significant 4-inch to 7-inch drop, giving you the ability to achieve the exact ride height and rake your build requires.

The R120-200 system offers total independent adjustability. The panhard bar, torque arm, trailing arms, and bracket mounts can be tuned without affecting one another, allowing for precise chassis setup. The included single adjustable shocks come with 200 lb/in springs and are 100% dyno tested and serialized to ensure consistent performance out of the box.

• Complete bolt-in installation with all necessary hardware included
• Provides 4" to 7" of ride height adjustability
• Independent torque arm design eliminates suspension binding
• Single adjustable shocks for simplified tuning of compression and rebound
• Includes 200 lbs/in coil-over springs
• Manufactured in QA1's Lakeville, Minnesota facility
• Manufacturer Part Number: R120-200

Fits 1963-1972 Chevrolet C10 Pickup, Panel, and Suburban models originally equipped with coil-spring rear suspension.

The QA1 R110-200 bolt-on rear suspension system is engineered to modernize your 1963-1972 C10 by converting the factory coil-spring setup to high-performance adjustable coilovers. This system provides up to a 6-inch total drop, allowing you to achieve a slammed stance while significantly improving handling and ride quality. The tubular steel truck arms feature integrated pinion angle adjustment, allowing for precise wheelbase centering and drivetrain alignment without the need for angled shims.

To ensure predictable cornering and stability, the kit includes an adjustable panhard bar with multiple mounting locations to correct roll center geometry based on your ride height. The single-adjustable coilovers are relocated to the outside of the frame rails, closer to the wheels, which increases cornering stability and creates additional clearance for popular aftermarket rear-mounted fuel tanks. This entire system is designed for a straightforward bolt-on installation that does not require removing the truck bed.

• Manufacturer Part Number: R110-200
• Adjustability: Single-adjustable shock valving
• Spring Rate: 200 lbs/in (Medium)
• Lowering Range: Up to 6" total drop
• Construction: Heavy-duty tubular steel truck arms
• Installation: Bolt-on design; no bed removal required
• Manufacturing: Made in the USA

The QA1 N Series NMR12 Injection Molded Carbon Steel rod end is engineered for low-load, moderate-oscillation applications where component integrity is paramount. Unlike standard rod ends that require drilled injection holes, the QA1 N Series features a unique race compound molded directly into the body. This design preserves the full structural strength of the carbon steel housing while providing a precise, low-friction interface.

Construction features include a ball manufactured from heat-treated 52100 bearing steel, which is hard chrome plated and precision ground for smooth operation. The race is composed of PTFE-reinforced Nylon 12, selected for its high wear resistance and low moisture absorption properties. The carbon steel body is finished with a protective coating for enhanced corrosion resistance in various environments.

• Part Number: NMR12
• Series: N Series (Injection Molded)
• Thread Size: 3/4-16 Male Right Hand
• Bore Diameter: 0.750 inches
• Body Material: Carbon Steel (Protective Coated)
• Ball Material: 52100 Bearing Steel (Heat Treated, Hard Chrome Plated)
• Race Material: PTFE Reinforced Nylon 12
• Design: No-hole injection molded race for maximum housing strength

The QA1 N Series (NML12) injection-molded rod end is engineered for low-load, moderate-oscillation applications where precision and durability are paramount. This series utilizes a unique manufacturing process that eliminates the need for drilled holes in the rod end body, preserving the full structural integrity of the carbon steel housing. The body is finished with a protective coating to ensure long-lasting corrosion resistance in various environments.

At the heart of this rod end is a 52100 bearing steel ball that has been heat-treated, hard chrome plated, and precision ground for smooth operation. The ball is housed within a reinforced Nylon 12 race infused with PTFE, providing a low-friction interface with excellent moisture resistance and high wear properties. This design ensures consistent performance without the maintenance requirements of traditional metal-to-metal joints.

• Part Number: NML12
• Thread: 3/4-16 Male (Left Hand)
• Bore Diameter: 0.750 in
• Body Material: Protective coated carbon steel
• Ball Material: Heat-treated 52100 bearing steel, hard chrome plated
• Race Material: Injection-molded reinforced Nylon 12 with PTFE
• Features: Low friction, low moisture absorption, and high wear resistance

The QA1 MXM Series Endura male rod end is engineered for high-strength metric applications such as 4-link systems and ladder bars. Designed to withstand heavy shock loads, this heavy-duty rod end features an increased cross-sectional thickness for superior tensile strength and long-term durability in demanding motorsport environments.

Constructed with a heat-treated chromoly steel body and a protective coating for corrosion resistance, this rod end utilizes a 52100 bearing steel ball that is heat-treated, hard chrome-plated, and precision-ground. The injection-molded Nylon/PTFE race provides a self-sealing and self-lubricating interface that keeps dirt and debris out while maintaining essential metal-to-metal support.

• Manufacturer Part Number: MXMR10
• Configuration: Male / Right Hand Thread
• Bore Size: 10mm
• Thread Size: M10x1.5
• Body Material: Heat-Treated Chromoly Steel
• Ball Material: Hard Chrome-Plated 52100 Bearing Steel
• Race Material: Nylon/PTFE (Self-Lubricating)
• Design: Metal-to-metal support for heavy shock loads

Fits 1994-2004 Ford Mustang Base, GT, SVT Cobra, Mach 1, and Bullitt models.

The QA1 MUK02 tubular K-member is engineered to shed significant front-end weight while providing the clearance and geometry needed for high-performance applications. Constructed from American-made HSLA (High-Strength Low-Alloy) steel, this unit weighs only 25 lbs—cutting over 50% of the weight compared to the factory stamped-steel component. Whether you are building a dedicated drag car, an autocross machine, or a Pro-Touring street build, this K-member improves handling by maintaining optimum anti-dive geometry and minimizing bump steer on lowered stances.

Designed for a straightforward bolt-in installation, this K-member retains the factory wheelbase and track width, ensuring your current wheel and tire fitment remains unchanged. The tubular design also provides much-needed room for large-tube headers and aftermarket oil pans. Note that engine mounts are sold separately to allow for various engine swap configurations.

• Material: American-made HSLA steel with a durable finish
• Weight: 25 lbs (over 50% lighter than OE)
• Design: Maintains factory wheelbase and track width
• Performance: Optimized anti-dive geometry and reduced bump steer
• Clearance: Increased room for headers and engine maintenance
• Manufacturer Part Number: MUK02

Fits 1979-1993 Ford Mustang (Base, GT, LX, SVO, and SVT Cobra). Swap in the QA1 MUK01 Tubular K-Member to shed significant front-end weight and improve the suspension geometry of your Fox Body. Engineered for street performance, drag racing, and autocross, this bolt-in component is constructed from American-made HSLA steel. At only 25 lbs, it is over 50% lighter than the factory K-member, providing a massive reduction in unsprung weight and improved header clearance for high-performance exhaust setups.

• Replaces heavy factory K-member with 25 lb tubular HSLA steel design
• Maintains factory track width and wheelbase for consistent wheel/tire fitment
• Optimized anti-dive geometry and minimized bump steer for lowered vehicles
• Increased header and oil pan clearance for easier engine maintenance and swaps
• Bolt-in installation using factory mounting points
• Manufacturer Part Number: MUK01

Note: This unit is provided without engine mounts to allow for custom engine configurations; bolt-in engine mounts are sold separately. For maximum performance and geometry correction, QA1 tubular control arms are recommended.

The QA1 MT103K Heavy-Duty Coil-over bracket kit provides a robust solution for adding coil-over suspension to custom car or truck builds. Engineered specifically for heavier vehicles, this kit utilizes double-shear bracketry to provide the necessary structural strength and support required for both high-performance street and racing applications.

This universal weld-on kit includes axle mount brackets designed for 3.00" diameter axle tubes along with upper shock mounting tabs. The axle-mounted brackets offer 9" of total height adjustment in 3/4" increments, allowing for precise control over vehicle stance and suspension geometry. When paired with QA1 coil-over shocks and springs, it creates a professional-grade suspension solution for custom fabrications.

• Designed for heavy-duty vehicle applications and custom builds
• Double-shear bracketry for maximum strength and safety
• 9" of total height adjustment in 3/4" increments
• Weld-on axle brackets fits 3.00" diameter tubes
• Includes upper shock mounting tabs and all necessary mounting hardware
• Made in the USA
• Manufacturer Part Number: MT103K

The QA1 MT100K Adjustable Shock Mount Kit provides a reliable DIY solution for customizing your suspension geometry. Specifically engineered for 3in diameter axle tubes, this kit allows you to easily convert between shock lengths to accommodate changes in ride height or suspension travel. It is a versatile choice for builders working with QA1 drag racing, street performance, or street rod adjustable shocks.

Constructed from high-strength steel in the USA, these mounts are built to handle the stresses of performance driving. The adjustable design gives you the flexibility to fine-tune your shock positioning for optimal dampening performance and clearance. This complete kit includes all necessary mounting hardware to streamline the installation process.

• Designed for universal DIY installation on 3in axle tubes
• Compatible with QA1 drag racing, street performance, and street rod shocks
• Adjustable design allows for easy shock length conversion
• Fabricated from heavy-duty steel for durability
• Includes all required mounting hardware
• Proudly Made in the USA
• Manufacturer Part Number: MT100K

Fits 2003-2011 Ford Crown Victoria models including Base, LX, Police Interceptor, and LX Sport.

The QA1 Pro Coil System provides a direct-fit solution for 2003-2011 Crown Victoria owners looking to upgrade their front suspension with adjustable ride height and valving control. These single-adjustable coil-overs feature a lightweight billet aluminum body that is fully threaded, allowing for precise height adjustment to achieve the perfect stance or to fine-tune weight balance for improved handling characteristics.

Engineered for ease of use, these shocks allow you to adjust valving to match your driving style. Every shock is 100% dyno tested and serialized to ensure consistent performance out of the box. Designed as a bolt-in upgrade, this system eliminates the guesswork of matching separate shocks and springs while offering a serviceable and rebuildable design for long-term durability.

• Single-adjustable shocks for simultaneous compression and rebound tuning
• Lightweight billet aluminum construction for reduced unsprung weight
• Includes 9-inch springs with a 650 lbs/in spring rate
• Fully threaded shock body for adjustable ride height
• 100% dyno tested and serialized by QA1
• Serviceable and rebuildable by QA1 authorized centers
• Easy bolt-in installation to factory points
• Made in the USA
• Manufacturer Part Number: MS431-09650

Fits 2003-2011 Ford Crown Victoria models including Base, LX, Police Interceptor, and Special Edition.

The QA1 Pro Coil System provides a bolt-in solution for 2003-2011 Ford Crown Victoria owners looking to achieve precise ride height control and suspension tuning. These single-adjustable front coilovers feature a lightweight billet aluminum threaded body that allows you to set the perfect stance and corner balance your vehicle for superior handling. Each system is equipped with 9-inch springs featuring a 550 lbs/in rate, ideal for maintaining stability and performance in various driving conditions.

• Manufacturer Part Number: MS431-09550
• Lightweight billet aluminum coil-over shocks
• Single adjustable valving controls compression and rebound simultaneously
• 9-inch high-performance springs with 550 lbs/in spring rate
• Fully threaded shock body for ride height adjustability
• 100% dyno tested and serialized for consistency
• Serviceable and rebuildable by QA1 authorized service centers
• Direct bolt-in installation for ease of use
• Proudly made in the USA

Fits 2003-2011 Ford Crown Victoria models, including Police Interceptor, LX, and LX Sport trims.

The QA1 Pro Coil System (MPN MS431-09450) provides precision ride height and valving control for the front suspension of your Ford Crown Victoria. Engineered for a direct, bolt-in installation, this system features a single-adjustable shock that allows you to tune the rebound and compression simultaneously. The fully threaded billet aluminum shock body provides the flexibility to set your stance exactly where you want it while improving overall vehicle weight balance and handling response.

• Spring Rate: 450 lbs/in with a 9-inch spring length.
• Adjustability: Single-adjustable valving for synchronized damping control.
• Construction: Lightweight billet aluminum shock bodies with a threaded exterior.
• Quality Assurance: 100% dyno tested and serialized for performance consistency.
• Serviceability: Fully rebuildable and serviceable by QA1 authorized centers.
• Manufacturing: Proudly made in the USA.
• Part Number: MS431-09450

Fits 1967-1973 Ford Mustang models, including Base, Mach 1, Grande, Boss 302/351/429, and Shelby GT-350/GT-500.

The QA1 Pro Coil System is a high-performance front suspension upgrade designed to modernize the handling and stance of classic Mustangs. This single-adjustable kit features lightweight aluminum shock bodies paired with 10-inch coil springs at a 450 lb/in rate. This specific spring rate is engineered for aggressive street performance and restomod applications, providing maximum roll control and sharp steering response.

The system utilizes a single adjustment knob to simultaneously fine-tune rebound and compression through 18 valving settings, allowing you to quickly transition from a comfortable cruise to a firm track setup. The threaded shock body enables precise ride height adjustments from factory stock height down to a 2-inch drop. Designed as a direct bolt-in solution, this kit installs into factory mounting locations without the need for cutting or welding.

• Manufacturer Part Number: MS402-10450C
• Damping Control: Single adjustable with 18 rebound/compression settings
• Spring Specifications: 10-inch length with 450 lb/in spring rate
• Ride Height Range: Factory stock to -2 inches
• Materials: Machined aluminum shock body and powder-coated high-tensile steel springs
• Compatibility: Works with factory or QA1 tubular control arms and sway bars
• Installation: Direct bolt-in; no welding or chassis modification required

Fits 1967-1973 Ford Mustang (Base, Boss, Grande, Mach 1, and Shelby models).

The QA1 Pro Coil System provides a precision front suspension upgrade for classic Mustangs, combining damping adjustability with ride height control. This single-adjustable system allows you to fine-tune both compression and rebound simultaneously via 18 distinct settings, making it easy to transition from comfortable street cruising to firm, responsive handling. The kit features an aluminum-bodied shock and a 10-inch, 400 lb/in coil spring designed to support restomod and street-performance builds.

Engineered as a direct bolt-in solution, this system requires no welding or major modifications to your chassis. It offers a ride height adjustment range from factory stock down to 2 inches lower, allowing you to achieve the perfect stance while improving suspension geometry and tire fitment.

• Damping Control: Single adjustable knob with 18 settings for simultaneous rebound and compression tuning.
• Spring Specs: 10-inch length with a 400 lb/in spring rate, ideal for street performance.
• Premium Materials: Lightweight aluminum shock bodies and powder-coated springs for long-term durability.
• Ride Height Range: Adjusts from factory height to -2 inches.
• Installation: Bolt-in design; compatible with factory or QA1 tubular control arms.
• MPN: MS402-10400C

Fits 1964-1966 Ford Mustang Base and Shelby GT-350/GT-350H models.

The QA1 Pro Coil System is a comprehensive front suspension upgrade designed to replace outdated factory shock and spring configurations with modern, adjustable performance. This kit provides a significant improvement in handling and ride quality, allowing owners of classic 1964-1966 Mustangs to bridge the gap between vintage style and contemporary driving dynamics. The system features lightweight aluminum shocks with a single-adjustable knob, giving you simultaneous control over 18 settings of rebound and compression damping to suit your specific driving environment.

Engineered for a true bolt-in installation, this system requires no cutting, welding, or chassis fabrication. It integrates seamlessly with either factory control arms or QA1 tubular components. The included 10-inch high-tensile springs feature a 350 lb/in rate, ideal for street performance and restomod applications. This system also enables precise stance tuning, offering ride height adjustability from stock level down to a 2-inch drop.

• Manufacturer Part Number: MS401-10350C
• Adjustment Type: Single Adjustable (18 valving settings)
• Spring Rate: 350 lbs/in
• Spring Length: 10 inches
• Ride Height Range: Stock to -2" lowering
• Material: Lightweight machined aluminum shock bodies
• Installation: Direct bolt-on; compatible with factory or QA1 control arms
• Hardware: Includes all necessary premium mounting hardware

Fits all 1997-2013 Chevrolet Corvette models, including Base, Z06, ZR1, Grand Sport, and special editions (V8-5.7L / V8-6.0L / V8-6.2L / V8-7.0L).

Replace your Corvette's factory transverse leaf spring suspension with the QA1 MOD Series Pro-Coil conversion kit. Designed for high-performance street and competitive track use, these 4-way adjustable coilovers allow for independent tuning of high-speed and low-speed compression and rebound. The modular design features QuickTune technology, utilizing dry valve packs that can be swapped without removing the shocks from the car or exposing the oil to contaminants.

The nitrogen-charged piggyback canisters are engineered to clear factory suspension geometry without requiring a toe link relocation kit. This system allows for precise ride height adjustments, offering a 1.0" to 2.0" drop on base models and a 0.5" to 1.5" drop on Z06 models to lower the center of gravity and improve corner balancing.

• 4-way adjustable high and low-speed bleed for precise weight transfer control
• QuickTune modular valve packs for rapid, track-side re-valving
• 8-inch high-tensile springs with a 550lb/in rate and 2.25" ID
• Hard-anodized aluminum shock bodies with piggyback canisters
• 100% dyno tested and serialized
• Bolt-on installation using factory mounting points
• Note: Models equipped with electronic ride control require Real Time Damping (RTD) simulators
• Manufacturer Part Number: MG455-08550
• Made in the USA

Fits select 1967-1974 Buick Apollo, Chevrolet Camaro and Nova, Oldsmobile Omega, and Pontiac Firebird and Ventura.

The QA1 MOD Series GM Pro Front Coil-Over System offers an unprecedented level of tunability for classic GM F-body and X-body platforms. Engineered for high-performance handling and stance control, this system features QA1's innovative QuickTune Technology. These dry modular valve packs allow you to swap valving in minutes without unsealing the shock, interrupting the oil path, or risking air contamination. Once your base valving is set, the 4-way adjustable design provides independent control over high-speed and low-speed compression and rebound via an adjustable low-speed bleed.

Built from high-grade aluminum, the MG401-10450A utilizes a nitrogen-charged canister available in piggyback or remote configurations to fit tight wheel wells. The base eyelet is fully indexable, allowing you to unbolt and reorient the canister for the best possible clearance. Each shock is 100% dyno tested and serialized at QA1's Minnesota facility to ensure consistent performance out of the box.

• QuickTune Technology: Modular dry valve packs for easy valving changes without oil loss.
• Adjustability: 4-way independent high and low-speed bleed for precise force curve tuning.
• Construction: Lightweight aluminum body with a 10-inch, 450lbs/in pigtail spring.
• Versatile Mounting: Indexable base eyelet and flexible canister mounting (piggyback or remote).
• Quality Assurance: 100% dyno tested and serialized; made in the USA.
• Part Number: MG401-10450A

Fits 1967-1973 Ford Mustang models, including Base, Boss 302/351/429, Grande, Mach 1, and Shelby GT-350/GT-500/GT-500KR.

The QA1 Pro Coil System transforms the front suspension of your classic Mustang with modern double-adjustable damping technology. This kit features lightweight aluminum shocks with independent rebound and compression controls, allowing you to fine-tune the suspension for street comfort or track-ready handling without removing the shocks from the vehicle. The included 10-inch high-tensile springs are rated at 400 lbs/in, providing an ideal balance for restomod builds and performance-oriented street cars.

Engineered as a direct bolt-in solution, this system requires no welding or cutting for installation. The threaded shock bodies provide ride height adjustability from factory stock height down to a 2-inch drop, giving you total control over the vehicle's stance and center of gravity while maintaining proper suspension geometry.

• Manufacturer Part Number: MD402-10400C
• Double adjustable shocks with 18 independent rebound and 18 compression settings
• 10-inch coil springs with a 400 lb./in. spring rate
• Ride height adjustable from factory height to 2-inches lower
• Lightweight aluminum shock bodies with premium hardware
• Direct bolt-in installation with no welding required
• Compatible with QA1 tubular control arms and sway bars

The QA1 MCOM-T Series spherical bearing (MPN: MCOM16T) is a high-strength metric solution designed for suspension linkages and mechanical pivots. This 16mm bore bearing is engineered for durability, featuring a heat-treated chromoly steel race with a protective coating for superior corrosion resistance.

The internal ball is manufactured from precision-ground 52100 bearing steel, heat-treated and hard chrome plated to ensure smooth articulation and reduced wear under load. To maintain maintenance-free operation, the MCOM16T includes a self-lubricating PTFE liner that reduces friction and eliminates the need for external grease.

• Manufacturer Part Number: MCOM16T
• Bore Diameter: 16mm
• Ball Material: 52100 Bearing Steel (Heat Treated, Hard Chrome Plated)
• Race Material: Chromoly Steel (Heat Treated, Protective Coated)
• Liner: Self-Lubricating PTFE (MCOM-T Series)
• Construction: Precision Ground for tight tolerances

The QA1 MOD Series (M911PR) redefines suspension tuning with its innovative QuickTune Technology. This right-hand piggyback coil-over shock features dry modular valve packs that allow for rapid revalving without opening the oil path or risking fluid contamination. This unique design enables trackside adjustments to compression and rebound characteristics in minutes, ensuring your vehicle stays optimized for changing conditions.

Built with 4-way adjustability, the MOD Series provides independent control over high and low-speed bleed. The nitrogen-charged piggyback canister offers a compact footprint for tight clearance areas, while the indexable base eyelet allows you to unbolt and reorient the mount for the perfect canister placement. Every shock is 100% dyno tested and serialized at QA1’s Lakeville, Minnesota facility to ensure consistent performance out of the box.

• QuickTune Technology: Modular dry valve packs for easy valving changes without oil loss
• Adjustability: 4-way adjustable high and low-speed bleed for precise force curve control
• Construction: Nitrogen-charged piggyback reservoir with indexable bearing mounts
• Dimensions: 14.875-inch compressed / 23.625-inch extended length
• Quality Assurance: 100% dyno tested and serialized
• Origin: Proudly made in the USA
• Part Number: M911PR

The QA1 MOD Series coil-over shock absorber provides professional-grade suspension tuning with its innovative QuickTune Technology. This modular system allows for rapid valving changes using dry valve packs that can be swapped without opening the shock, preventing oil loss or debris contamination. The M911PL is engineered for high-performance applications where precise damping control is required.

Equipped with a nitrogen-charged piggyback canister, this shock features an indexable base eyelet that can be unbolted and reoriented to suit specific mounting clearance needs. The double-adjustable design includes independent control over compression and rebound, supplemented by 4-way high and low-speed bleed adjustments for a highly customizable force curve. Every unit is manufactured in QA1’s Lakeville, Minnesota facility and is 100% dyno tested and serialized.

• Part Number: M911PL
• Configuration: Piggyback, Left Hand orientation
• Mounting: Bearing Mount
• Dimensions: 14.875" Collapsed / 23.625" Extended
• QuickTune modular valve pack system for easy revalving
• 4-way adjustable high and low speed bleed
• Nitrogen-charged canister for consistent performance
• Indexable base eyelet for flexible installation
• Made in the USA

The QA1 MOD Series piggyback coil-over shock absorber (M511PR) provides elite-level tunability through revolutionary QuickTune Technology. Designed for right-hand installation with a bearing mount, this nitrogen-charged shock allows for rapid revalving using dry modular valve packs—changing the valving without opening the oil path or risking contamination. This design enables independent control over compression and rebound characteristics to suit specific track conditions or vehicle setups.

Engineered for versatility, the M511PR features a 11.5-inch compressed and 16.875-inch extended length. The indexable base eyelet can be unbolted and rotated to ensure optimal canister placement even in tight mounting configurations. Every unit is manufactured in QA1’s Lakeville, Minnesota facility and undergoes 100% dyno testing to ensure consistent, serialized performance.

• QuickTune Technology: Interchangeable dry modular valve packs for fast revalving without oil loss
• 4-Way Adjustable: Independent high and low-speed bleed control for compression and rebound
• Configuration: Nitrogen-charged piggyback canister design
• Mounting: Indexable base eyelet and bearing mount for flexible installation
• Specifications: 11.5" compressed length, 16.875" extended length
• Quality: 100% dyno tested and serialized; Made in the USA
• Manufacturer Part Number: M511PR