Classic Mustang Suspension Buyer's Guide (1964-70)
Table of Contents
Find the Right QA1 System for Your Classic Mustang
Whether you’re restoring a daily driver, crafting a street-ready restomod, or building a pro-touring machine, upgrading your Classic Mustang’s suspension is one of the best ways to improve ride quality, handling, and confidence behind the wheel.
QA1’s line of Full Vehicle Handling Kits, Front Pro Coil Systems, and Rear 4-Link Systems are engineered to transform your 1964-70 Mustang - no matter your skill level or performance goals. Here’s how to choose the right setup for your build.
STAGE 1: STREET CRUISER / WEEKEND DRIVER
A better ride for the classic Mustang enthusiast
If your goal is to make your Mustang handle and ride like a modern car - without over-complicating the build - QA1’s Level 1 Full Vehicle Handling Kits are the perfect choice.
These systems completely replace the front suspension with bolt-on front coilovers adding a 1 ⅛" front sway bar and single adjustable rear shocks. You’ll get a lower stance, smoother ride, and more predictable cornering, all while keeping your factory rear axle.
Highlights:
- Ideal for: Daily drivers, weekend cruisers, or restomods that keep factory drivetrains
- Single adjustable coilovers (ride and handling in one easy adjustment)
- Front and rear kits work together as a complete system
- Bolt-on installation
- Adjustable ride height: stock to –2”
Recommended systems
STAGE 2: PERFORMANCE STREET / PRO-TOURING BUILD
Tunable handling for enthusiasts who want more control
If you’re pushing your Mustang harder - maybe running wider tires, more power, or occasional track days - QA1’s Level 2 Full Vehicle Handling Kits deliver the next step in performance.
With double adjustable coilovers, you can fine-tune both compression and rebound damping independently. This means you can soften things up for cruising or tighten it down for aggressive cornering, giving you total control over how your Mustang feels.
Highlights
- Ideal for: Restomods, autocross cars, and high-horsepower street builds
- Double adjustable coilovers front and rear for precision tuning
- Tubular control arms improve geometry and reduce flex
- Weld-in 4-link delivers exceptional traction and ride quality
- Adjustable stance and corner balance capability
Recommended systems
STAGE 3: CUSTOM / HIGH-POWER BUILDS
Full adjustability, maximum strength, and modern performance — built for serious power
If you’re building a Mustang that’s designed to perform, whether it’s a 600+ horsepower restomod, a pro-touring machine, or a street car that sees serious track time, QA1’s Level 2 Full Vehicle Handling Kit with 9” Housing is the top choice.
These systems combine QA1’s double adjustable coilovers, triangulated 4-link suspension, and a fabricated 9” rear housing designed to handle serious power. Together, they deliver unmatched traction, geometry precision, and fine-tuned handling for builders who demand both performance and durability.
Unlike piecing together components from different brands, QA1’s all-in-one approach ensures every part works together, from front control arms to rear suspension, creating a balanced, predictable setup you can trust on the street or track.
Highlights
- Ideal for: Pro-touring builds, high-horsepower restomods, and performance street cars
- Double adjustable coilovers provide independent compression and rebound control
- Fabricated 9” rear housing bolts directly to QA1’s 4-link system — no custom fab required
- Heavy-duty 3” OD, ¼” wall axle tubes and 31-spline alloy axles support big power
- Triangulated 4-link eliminates wheel hop and improves traction under hard acceleration
- Front Pro Coil system and tubular control arms enhance geometry and cornering response
- Adjustable ride height: stock to –2” in the front and stock to –3” in the back
Recommended components
QA1 Level 2 Full Vehicle Handling Kit with QA1 9” Housing – 64-66 Mustang
QA1 Level 2 Full Vehicle Handling Kit with QA1 9” Housing – 67-70 Mustang
FINAL THOUGHTS
Whether you’re updating your Mustang for weekend cruising or transforming it into a corner-carving restomod, QA1 has a suspension system designed to meet your needs — from simple bolt-on comfort to fully tunable performance.
Explore the full lineup of QA1 Mustang Suspension Systems and see how easy it is to bring your classic into the modern era.
FAQs
Can I run coilovers and leaf springs together on my Mustang?
Front coil-over and rear leaf springs are ok, but you do not want to add coil-overs with the rear leaf springs. Coilovers and leaf springs both support the car’s weight, so using them together creates an extremely firm suspension. Coilovers are meant to be paired with a link-style rear suspension, like QA1’s triangulated 4-link, which properly locates the axle while providing adjustable ride height and damping control.
What does a 4-link suspension do that leaf springs don’t?
A 4-link system separates axle location and spring function for better control and geometry. Unlike leaf springs, which flex and twist under load, a 4-link maintains pinion angle, reduces wheel hop, and improves traction. The result is smoother launches, more consistent cornering, and a ride that feels planted - especially when paired with QA1’s double adjustable coilovers.
Why upgrade to a QA1 9-inch housing if my Mustang already came with a 9-inch?
Factory 9-inch housings were never designed for today’s power levels or suspension loads. QA1’s fabricated 9-inch housings feature thicker ¼-inch wall axle tubes, formed trailing arm brackets, and precision-welded construction that minimizes flex under hard acceleration. They also include built-in fill, drain, and vent ports for easier servicing. If you’re upgrading to a QA1 4-link, the QA1 housing bolts right in with new 31 spline axles - no fabrication.
Will this suspension work with factory steering components?
Yes. QA1’s front suspension systems are engineered to work seamlessly with factory steering linkages. For builders wanting even tighter steering response, Proforged steering kits have been tested with QA1 systems and are an excellent upgrade for added precision and reliability.
How much power can QA1 suspension systems handle?
QA1’s 4-link kits with the 9” housing and 31-spline axles are rated for up to 650+ horsepower. The reinforced brackets, heavy-wall tubing, and high-strength alloy axles are designed for both high-performance street cars and serious track builds.
