QA1 MS303-08500 Mustang II S-Adj Coilover Kit 500 lb. 1974-1978 Ford Mustang For Sale

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Part Brand: QA1

Part Number: MS303-08500

• 1974–1978 Ford Mustang II (All Trims incl. Base, Ghia, Mach 1, Cobra II, I4 2.3L / V6 2.8L / V8 5.0L)

• Designed specifically for the factory 1974–1978 Ford Mustang II front coil-over suspension — uses the OEM Mustang II shock mounting geometry with a 7/16 in. lower eyelet bushing.
• This kit is also widely used in Mustang II front suspension conversion applications installed in hot rods, street rods, muscle cars, and custom chassis builds — verify lower mount bolt diameter (7/16 in.) and upper mounting configuration before ordering for non-OEM applications.
• Includes 8 in. 8MB500 tapered chrome coil springs (500 lb./in., 3.5 in. upper / 2.5 in. lower I.D.) designed specifically for the Mustang II coil-over seat geometry.
• For double-adjustable valving on the same platform, order QA1 MD303-08500. For non-adjustable, order QA1 MS301-08500.
• Sold as a pair — one kit covers both front shocks.

• 18-position single-adjustable rebound knob allows simple on-car tuning from soft street to firm performance settings.
• Machined aluminum shock body reduces unsprung weight and provides long-term corrosion resistance vs. steel-bodied alternatives.
• Fully threaded shock body enables external ride height adjustment via spanner wrench to achieve the perfect stance or tune corner weight balance.
• 500 lb./in. chrome-plated tapered 8MB500 springs with 3.5 in. upper I.D. and 2.5 in. lower I.D. — matched to the Mustang II coil-over seat geometry and designed for performance street use.
• 7/16 in. lower eyelet bushing mount provides a stable, low-NVH installation at the stock lower shock mount location.
• 100% dyno tested and serialized before shipment; serviceable and rebuildable by QA1 authorized service centers.
• Proudly made in the USA in Lakeville, MN; backed by QA1's 1-year warranty.

• Application: 1974–1978 Ford Mustang II (Front) / Mustang II IFS Conversion Builds
• Shock Series: MS303 (Mustang II Pro Coil — Single-Adjustable)
• Adjustability: Single-Adjustable Rebound (18 positions)
• Spring Rate: 500 lbs./in.
• Spring Length: 8 in.
• Spring Style: Tapered (8MB500) — 3.5 in. Upper I.D. / 2.5 in. Lower I.D.
• Spring Finish: Chrome Plated
• Shock Body Material: Machined Aluminum (anodized)
• Collapsed Length: 7.88 in. (center-to-center)
• Extended Length: 11.00 in. (center-to-center)
• Lower Mount: 7/16 in. Eyelet Bushing
• Quantity: Sold as a Pair (2 shocks + 2 springs)
• Warranty: 1 Year

• 2x MS303 Single-Adjustable Mustang II Pro Coil Shocks (aluminum)
• 2x 8 in. 500 lb./in. Chrome Tapered Coil Springs (8MB500)
• 1x Set Mounting Hardware

The QA1 MS303-08500 is a front Pro Coil single-adjustable coil-over system designed specifically for the 1974–1978 Ford Mustang II independent front suspension. It replaces the factory shock and spring combination with a matched pair of 18-position single-adjustable aluminum coil-over shocks and 500 lb./in. chrome-plated tapered springs, giving Mustang II owners adjustable ride height, tunable rebound damping, and a significant performance improvement over the OE setup. The machined aluminum shock body reduces unsprung weight, and the fully threaded body allows on-car ride height adjustment via a spanner wrench for stance customization or corner weight balancing.

Beyond its factory Mustang II fitment, this kit is one of the most popular coil-over choices for the countless hot rods, classic muscle cars, and custom chassis builds that have adopted Mustang II IFS geometry as a conversion platform. The 500 lb./in. spring rate and 8 in. tapered 8MB500 chrome spring are matched to the Mustang II coil-over seat dimensions (3.5 in. upper I.D., 2.5 in. lower I.D.) and suit street-performance builds seeking a firm, responsive front end. The 7/16 in. lower eyelet bushing matches the factory lower shock mount bolt diameter. For builds requiring more tuning range, the double-adjustable version (MD303-08500) provides independent compression and rebound control across 324 combinations.

*Parts are for USA spec vehicles, please contact us to verify fitment on JDM & international models.

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• Canada customers - If does not collect import & duty fees during checkout, the shipping carrier will collect them prior to delivery.

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