The Ultimate QA1 Suspension Guide for Classic 1964–1970 Mustangs

How to Pick the Right QA1 Suspension System for Your Classic Ford Mustang (From Street Cruisers to High-Power Restomods)

If you’re restoring or upgrading a 1964–1970 Ford Mustang, optimizing the suspension should be at the top of your build list. Whether your goal is better everyday drivability, confident cornering on back roads, or track-ready performance, the right suspension setup transforms your Mustang’s ride quality, handling, and overall confidence behind the wheel.

At Stang-aholics, we now offer the complete QA1 suspension lineup — giving you access to premium handling upgrades designed specifically for classic Mustangs. From bolt-on street kits to fully tunable pro-touring systems, here’s a guide to help you choose the best suspension solution for your project.

Why Upgrade Your Classic Mustang Suspension?

Original suspension components on vintage Mustangs were designed for 1960s driving expectations — not modern roads or performance builds. Upgrading gives you:

  • Better ride comfort and predictability

  • Reduced body roll and dive under braking

  • Sharper steering response and cornering confidence

  • Improved traction and reduced wheel hop

All of this adds up to a Mustang that feels more planted and capable — whether you’re cruising Main Street or attacking a twisty back road.

Stage 1: Street Cruiser & Weekend Driver

Great Ride Quality With Minimal Complexity

Quick Overview: If your Mustang spends most of its time on the street and you want a smooth, modern ride with straightforward installation, a Level 1 suspension kit is an ideal starting point. These kits bring key upgrades like coil-over front suspension and single-adjustable rear shocks while keeping installation simple.

More Detail: Level 1 suspension systems are designed for classic Mustang owners who want a smoother ride, improved handling, and a cleaner stance without sacrificing comfort or originality. These street-focused suspension upgrades replace worn factory components with modern coil-over shocks, tubular control arms, and upgraded sway bars that dramatically improve ride quality and steering response. Installation is straightforward and typically requires no cutting or fabrication, making Level 1 kits ideal for daily drivers, weekend cruisers, and lightly restored Mustangs. The result is a noticeable reduction in body roll, better road feel, and a classic Mustang that drives more like a modern performance car while retaining excellent street manners.

QA1 Level 1 Suspension Kit for Classic Mustangs

What It Includes

  • Bolt-on front coil-over shocks

  • Tubular control arms for stronger geometry

  • Front sway bar to reduce body roll

  • Single-adjustable rear shocks

Why It’s Worth It

This setup improves ride quality, lowers your Mustang’s stance, and gives a noticeable boost in confidence over stock suspension — all without complex fabrication. These kits are perfect for daily cruisers, show cars, or weekend drivers.

Stage 2: Performance Street & Pro-Touring Builds

Tunable Suspension for Enthusiasts

Quick Overview: For street performance or restomod builds that see occasional spirited driving or track days, Level 2 suspension systems deliver next-level handling. These kits replace leaf springs with a rear 4-link system and use double-adjustable coilovers for precise tuning.

More Detail: Level 2 suspension systems take classic Mustang handling to the next level by adding full adjustability and increased rear traction. These performance-oriented kits typically include double-adjustable coilovers in the front and rear, along with a triangulated 4-link rear suspension that replaces factory leaf springs. This design allows the suspension to separate spring function from axle control, reducing wheel hop and improving grip during acceleration and cornering. Level 2 setups are perfect for pro-touring builds, autocross cars, and high-performance street Mustangs, offering the ability to fine-tune compression and rebound for different driving styles. Drivers benefit from improved balance, sharper turn-in, and a planted feel that inspires confidence on both the street and track.

QA1 Level 2 Suspension Kit for Classic Mustangs

Key Benefits

  • Independent compression & rebound tuning — dial in balance between comfort and control

  • Tubular control arms — improve geometry and reduce flex

  • Triangulated 4-link rear suspension — better traction, less wheel hop

  • Adjustable stance & corner balance

Perfect for autocross cars, high-power street builds, and restomods, Level 2 systems let you fine-tune your Mustang for anything from relaxed cruising to aggressive handling.

Stage 3: Custom / High-Power Builds

Maximum Performance & Strength

Quick Overview: If you’re building a Mustang with serious power — whether 600+ hp street monster, pro-touring machine, or track weapon — you need more than basic upgrades. High-end setups combine tunable coilovers with a fabricated 9-inch rear housing, 31-spline axles, heavy-wall tubes, and a true triangulated 4-link for the ultimate in traction and strength.

More Detail: Level 3 suspension systems are built for classic Mustang owners pushing serious power and demanding maximum handling capability. These advanced systems are engineered for pro-touring, track-focused, and high-horsepower builds, combining fully adjustable coilover suspension with a heavy-duty rear axle assembly and a true triangulated 4-link design. With reinforced mounting points, performance-grade components, and superior geometry, Level 3 systems deliver exceptional traction, stability, and control under extreme loads. This setup virtually eliminates wheel hop, keeps wide tires planted, and allows precise suspension tuning for aggressive driving conditions. For builders who want modern supercar-level handling from a vintage Mustang, Level 3 suspension upgrades provide the ultimate solution.

QA 1 Level 3 Complete Suspension Kit for Classic Mustangs

What Sets This Apart

  • Heavy-duty rear housing ready for high power

  • Double-adjustable coilovers front and rear

  • Eliminated wheel hop and increased traction under load

  • Balanced handling even with wide tires and aggressive cornering

This modular performance setup turns your classic into a modern-handling machine without sacrificing classic style or structural integrity. 

Key Suspension Upgrades You Should Know

Even if you’re not ready for a full handling kit, upgrading individual components can dramatically improve your Mustang’s behavior:

Control Arms

Tubular control arms replace weak stock parts, tighten up steering response, and improve suspension geometry — especially when paired with modern shocks.

Sway Bars

Upgrading to larger front and rear sway bars significantly reduces body roll and improves corner balance. Bolt-on sway bars are a simple way to enhance handling without a full suspension overhaul.

Adjustable Shocks & Coilovers

Single- or double-adjustable shocks let you tune ride comfort and control, making them a cornerstone upgrade for any serious suspension build.

Frequently Asked Suspension Questions

Can I mix coilovers with leaf springs?
Front coilovers can work with a leaf spring rear, but pairing coilovers with a leaf spring that also supports vehicle weight can make the ride excessively firm. A 4-link rear setup is highly recommended for a more balanced feel and improved rear suspension performance.

What does a 4-link system do that leaf springs don’t?
A 4-link setup separates axle location from spring function, improving geometry, eliminating rear wheel hop, and enhancing traction — especially when launching or cornering hard. The result is smoother launches, more consistent cornering, and a ride that feels planted and more in control - especially when paired with QA1’s double adjustable coilovers.

Are these kits compatible with factory steering?
Yes — QA1 systems are designed to work with stock steering linkages, though upgraded steering components like Proforged linkage kits and integral power steering gearboxes can enhance precision.

Why upgrade to a QA1 9-inch Rear Axle Housing if My Mustang already has a 9-inch housing?
Original 9-inch rearend housings were never engineered to handle the horsepower or suspension stress common in modern performance builds. QA1’s fabricated 9-inch housings are built with heavy-duty ¼-inch axle tubes, integrated trailing arm mounts, and high-precision welds that significantly reduce flex during hard launches and aggressive driving. For added convenience, each housing includes integrated fill, drain, and vent provisions to simplify maintenance. When paired with a QA1 4-link suspension, the housing installs as a direct bolt-in and comes ready with new 31-spline axles — delivering a stronger, cleaner upgrade without the need for custom fabrication.

Can a QA1 suspension handle high horsepower?
The QA1 4-link systems with a new high quality 9-Inch rear housing with reinforced brackets, heavy-wall tubing, and high-strength alloy 31-spline axles are rated up to approximately 650+ horsepower, making them suitable for serious high-performance street applications and mild track builds.

Final Thoughts

Upgrading a classic Mustang’s suspension is one of the most impactful ways to modernize drive quality, handling, and overall performance — whether your focus is cruising, weekend drives, or high-end performance builds.

At Stang-aholics, we’re proud to offer the full lineup of QA1 suspension systems for 1964–1970 Mustangs, complete with expert support and guidance to help you choose the right setup for your build.

Ready to Upgrade Your Mustang?

Explore our QA1 Suspension Category and find the right handling package for your classic ride: QA1 Suspension for Classic Mustangs.

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