Transform your 1967–1970 Mustang’s rear suspension with QA1’s complete bolt-in 4-link system, featuring a custom QA1 9-inch rear housing. This all-inclusive kit delivers modern handling, improved traction, and the durability to handle serious horsepower - all while retaining a clean, factory-style fit. Perfect for restomod builds and performance street cars, this setup eliminates the compromises of leaf-spring suspension for good.
MODERN HANDLING FOR YOUR CLASSIC MUSTANG
QA1’s triangulated 4-link system replaces leaf springs with a geometry-optimized setup that improves traction, stability, and ride quality. By eliminating axle wrap and keeping pinion angle consistent under load, your Mustang will launch harder, corner flatter, and drive smoother - whether you’re cruising or carving corners.
SINGLE ADJUSTABLE COILOVERS
This system includes QA1’s single adjustable shocks, offering 18 clicks of rebound and compression adjustment together. A single knob makes it easy to fine-tune comfort and performance, giving you complete control over how your Mustang rides and handles.
BUILT TO HANDLE BIG POWER
QA1’s fabricated 9-inch housing is designed to take abuse. Fully formed trailing arm brackets minimize flex, while 3” OD, ¼” wall axle tubes and 31-spline alloy axles provide the strength to handle up to 650 HP (housing rated to 800 HP). The result is a rigid, predictable suspension that’s ready for modern horsepower levels.
RIDE HEIGHT ADJUSTABILITY
Easily adjust ride height from factory level to 3” lower. Fine-tune your stance and handling without compromising geometry, tire clearance, or comfort - all with simple, tool-free adjusters.
FEATURES & BENEFITS
- Application-specific fit for 1967–1970 Ford Mustangs
- Complete system includes 9” rear housing, triangulated 4-link, and coilover shocks
- Single adjustable shocks with 18 clicks of rebound/compression control
- Adjustable ride height: factory to –3”
- Eliminates axle wrap and wheel hop for improved traction and control
- Heavy-duty fabricated 9” housing with 3” OD, ¼” wall axle tubes
- 31-spline 1541H alloy axles rated to 650 HP (housing rated to 800 HP)
- Big Ford “New Style Torino” flanges (2.5” offset) for easy brake compatibility
- 5x4.5” bolt pattern fits most aftermarket Mustang wheels
- Includes drain plug, fill plug, vent port, and jack pad for easy serviceability
- Weld-in installation with self-fixturing brackets for perfect geometry alignment
- Made in the USA with premium materials and hardware
EASY INSTALLATION
The QA1 4-link kit is designed for self-fixturing weld-in installation, ensuring accurate alignment with minimal fabrication. The included QA1 9” housing bolts in cleanly, providing a precise fit with QA1’s brackets and coilovers.
FITMENT NOTES
- Fits 1967–1970 Ford Mustangs
- Designed to work exclusively with included QA1 9” housing
- Weld-in installation required
- Factory wheel mounting surface: 59 3/8”
- Big Ford “New Style Torino” flanges (2.5” axle offset)
- 5x4.5” bolt pattern (standard Ford fitment)
- Requires 31-spline 9” third member (sold separately)
Specifications
- Vehicle PositionRear
- Shock ValvingSingle Adjustable
- Springs IncludedYes
- Spring Rate150lb/in.
- Axle Shaft Splines31
- Width (Wheel mounting surfaces)59 3/8in
- Brake FlangeBig Ford "New Style Torino"
- Brake Offset2.5"
- Bolt Pattern5x4.5 in
