64-66 Mustang QA1 4 Link Rear Suspension w/ 9 Inch Housing

Modern Handling with a Perfect Factory Fit

QA1’s triangulated 4-link system is designed specifically for early Mustangs, offering a geometry-correct layout that maintains proper pinion angle and eliminates common issues like axle wrap. The result is dramatically improved traction, sharper cornering, and a smoother, more predictable ride. Paired with the included custom QA1 9″ housing, this system ensures a precise fit and the durability required for today’s high-performance engines.

Single-Adjustable Coilovers for Personalized Performance

This kit includes QA1’s renowned single-adjustable coilovers, giving you 18 clicks of combined compression and rebound adjustment. With a simple turn of the knob, you can fine-tune your Mustang’s suspension for comfortable daily cruising or tighten it up for aggressive handling and spirited driving.

Built Strong for High-Horsepower Applications

At the heart of the kit is QA1’s heavy-duty 9″ housing featuring fully formed trailing-arm brackets, a fabricated steel center section, and robust 3″ O.D. axle tubes. This rugged construction supports up to 800 horsepower, making it ideal for modern V8 swaps and high-power builds. Included 31-spline alloy axles deliver long-lasting strength and smooth performance under load.

Customizable Ride Height & Stance

Achieve the ideal look and performance with an adjustable ride height that ranges from stock height down to 3″ lower. This flexibility allows you to set your preferred stance while keeping proper geometry, ensuring improved handling without sacrificing ride quality.

Kit Features & Benefits

• Complete QA1 4-Link Suspension System with 9” Ford Housing
  All-in-one rear suspension upgrade engineered for strength, performance, and precision fitment.

• Designed Specifically for 1964–1966 Ford Mustangs
  Application-specific components ensure proper geometry and seamless installation.

• Single-Adjustable Coilover Shocks
  Offers 18 clicks of rebound/compression adjustment for easy tuning of ride quality and handling.

• Customizable Ride Height
  Adjust from factory height down to –3” for the perfect stance without compromising suspension performance.

• Triangulated 4-Link Geometry
  Eliminates axle wrap and wheel hop, delivering improved traction, better cornering, and a smoother ride.

• Heavy-Duty Rear Housing Construction
  Features a fabricated center section and 3” O.D., ¼” wall axle tubes for maximum rigidity and durability.

• High-Strength 31-Spline Axles
  Made from 1541H alloy, rated for 650 HP, with the housing engineered to handle up to 800 HP.

• Big Ford “New Style Torino” Brake Flanges
  Ensures broad brake compatibility and easier aftermarket brake upgrades.

• 5×4.5” Wheel Bolt Pattern
  Compatible with a wide range of classic and modern Mustang wheel options.

• Weld-In, Self-Fixturing Brackets
  Provides accurate alignment and simplified installation for a professional-quality setup.

• Proudly Made in the USA
  Built with premium materials and high-quality hardware for long-lasting performance.