Already running one of QA1’s 4-Link Suspension Kits on your classic Mustang? The QA1 9” rear housing is the perfect upgrade to handle more horsepower, improve durability, and simplify serviceability. Designed specifically to integrate with QA1’s 4-link systems, this housing delivers strength, precision, and a true bolt-on fit.
ENHANCE YOUR EXISTING QA1 4-LINK
QA1’s fabricated 9” rear housing bolts directly to QA1’s Mustang 4-link suspension systems. It features fully formed trailing arm brackets that minimize flex under heavy loads, improving suspension response and long-term reliability. Whether you’re stepping up to more power or building a street-driven restomod, this housing provides the durability and alignment precision you need - without custom fabrication.
FEATURES & BENEFITS
- Fabricated steel center section engineered for maximum strength and rigidity
- Fully formed trailing arm brackets reduce flex under hard acceleration
- Heavy-duty 3” OD, ¼” wall axle tubes designed for high-performance builds
- 31-spline 1541H alloy axles rated for up to 650 HP; housing rated to 800 HP
- Big Ford “New Style Torino” flanges (2.5” axle offset) for easy brake compatibility
- Standard 5x4.5” bolt pattern fits a wide range of wheels
- Includes drain plug, fill plug, vent port, and jack pad for easy serviceability
- ½” x 3” wheel studs for improved fitment with alloy wheels
- Factory wheel mounting surface width for proper tire clearance - 1964–1966: 57 3/8”
- Durable semi-gloss powder coat finish resists corrosion and looks great
- Includes T-bolts, housing studs, and roller bearings for smooth operation
EASY INSTALLATION & SERVICEABILITY
QA1’s bolt-on housing design eliminates the need for cutting, welding, or additional fabrication. The integrated jack pad, fill and drain plugs, and vent port make servicing simple and clean. If you already have a QA1 4-link system, this housing bolts in place for a seamless upgrade - perfect for any street, strip, or pro-touring build.
HELPFUL SPECIFICATIONS
- Fits QA1 4-Link kits for 1964–1966 Ford Mustangs
- Factory wheel mounting surface: 57 3/8”
- Big Ford “New Style Torino” flanges with 2.5” axle offset
- 5x4.5” bolt pattern (standard Ford fitment)
- ½” x 3” wheel studs
- 2.770” hub diameter
- Requires third member for Ford 9” housings with 31-spline axles
FITMENT NOTES
- Fits QA1 4-link suspension systems only
- Center section (third member) sold separately
- Stock width housing recommended for stock wheel tubs
- Verify wheel and tire fitment on vehicle before installation
- Wheel studs are 1/2in-20 thread with 0.615in knurl
Specifications
- Axle Shaft Splines31
- Width at wheel mount surfaces57 3/8in
- Brake FlangeBig Ford "New Style Torino"
- Brake Offset2.5"
- Bolt Pattern5x4.5 in
