MS401-10400C Front Pro Coil Shock System, Single Adjustable, Ford, 10in. Spring, 400lb./in.

MS401-10400C Front Pro Coil Shock System, Single Adjustable, Ford, 10in. Spring, 400lb./in.

QA1

SKU
MS401-10400C
$854.95
Estimated Shipping Date: Jun 12, 2026
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Installation Guide
California Prop 65
Emissions Code 4

Upgrade your classic Mustang’s suspension with QA1’s Pro Coil System. Engineered for 1964–1966 Mustangs, this single adjustable coilover kit offers modern handling, ride quality, and stance adjustability in a straightforward, bolt-in package. Featuring a 10” coil spring with a 400 lb./in. rate, it’s an excellent choice for restomods and street-driven cars that need sharper handling and improved control.

MODERN HANDLING & CONTROL

Factory suspension designs limit tuning and performance. QA1’s single adjustable coilovers let you fine-tune rebound and compression together with 18 adjustment settings. With one knob, you can soften the ride for cruising or firm it up for aggressive driving, giving you the flexibility to match your Mustang’s style.

RIDE HEIGHT FLEXIBILITY

This system allows you to adjust ride height from factory stock height down to 2” lower. Whether you’re keeping an original look or going for a lower stance, QA1 Pro Coils let you achieve the right height without sacrificing suspension geometry or drivability.

EASY BOLT-IN INSTALLATION

No welding or cutting required. QA1 designed this system as a direct bolt-in replacement that installs with basic hand tools, making it a perfect upgrade for DIY enthusiasts.

FEATURES & BENEFITS

  • Application-specific fit for 1964–1966 Ford Mustangs
  • Single adjustable shocks with 18 rebound/compression settings
  • Includes 10” coil springs with a 400 lb./in. spring rate
  • Adjustable ride height: factory to –2”
  • Easy bolt-in installation - no welding required
  • Powder-coated springs and premium hardware for long-term durability
  • Complements QA1 tubular control arms and sway bars for a complete system

FITMENT NOTES

  • Fits 1964–1966 Ford Mustangs
  • Ride height adjustable: factory to –2”
  • Includes single adjustable shocks and 10” 400 lb./in. springs
  • Works with factory control arms or QA1 tubular control arms and sway bars
  • Bolt-in installation — no welding required

RECOMMENDED FRONT SPRING RATE CHART

YEAR MODEL SMALL BLOCK SPRINGS BIG BLOCK SPRINGS
1964-1966 Mustang 350 450
1967-1973 Mustang 400 500



Specifications

  • Spring Rate400lb/in.
  • Springs IncludedYes
  • Shock ValvingSingle Adjustable
  • Vehicle PositionFront

FREQUENTLY ASKED QUESTIONS (FAQ’s)

What spring rate comes with the QA1 MS401-10400C coilover kit?

This system includes 10” front coil springs with a 400 lb./in. spring rate, making it ideal for drivers looking for a balance of ride comfort and sharper handling response.

How much ride height adjustment do QA1 Pro Coils provide for a 1964–1966 Mustang?

:QA1 Pro Coils allow ride height adjustment from factory stock height down to 2 inches lower, giving you flexibility for stance and performance.

How do single adjustable QA1 coilovers work?

Single adjustable shocks use one knob to adjust rebound and compression together, offering 18 settings so you can easily tune comfort and performance.

Do QA1 coilover kits require modifications?

No. The MS401-10400C system installs as a direct bolt-in with basic tools and does not require welding or cutting.

What’s the difference between 350 lb./in. and 400 lb./in. QA1 springs?

The 350 lb./in. option provides a slightly softer ride, while the 400 lb./in. spring rate gives a firmer feel and improved handling response — ideal for drivers who want more control without going overly stiff.

Are QA1 single adjustable coilovers good for street use?

Yes. They’re designed for street performance, providing comfort for cruising and adjustability for more spirited driving when needed.

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