QA1 8MB600 Tapered Chrome Coil Spring 600 lb. 8 in. for Mustang II Coil-Over

Vehicle Fitment

• Universal - Designed for vehicles equipped with a Mustang II independent front suspension (IFS) coil-over conversion system using a 3.5 in. upper / 2.5 in. lower tapered coil-over seat.

Fitment Notes

• This is a semi-universal spring designed for Mustang II coil-over systems - verify your shock's collapsed length, extended length, and seat I.D. before ordering to confirm compatibility.
• Designed specifically for use with QA1 Mustang II Pro Coil coil-over kits featuring a 3.5 in. upper and 2.5 in. lower tapered spring seat.
• Not a direct vehicle-specific replacement spring - fitment depends on the coil-over system installed in the vehicle, not the vehicle's original OE spring spec.
• Available in multiple spring rates in the 8MB series: 8MB400, 8MB500, 8MB600, and 8MB700 - select rate based on vehicle weight, spring perch travel, and handling goal.
• For LS1-heavy front ends or performance builds with heavier front-end weight, the 600 lb. rate is commonly paired with QA1 GS401 or equivalent Mustang II coil-over shocks.

Features

• Manufactured from chrome silicon steel (CrSi) for maximum strength, consistency, and long service life under high-stress coil-over use.
• Cold wound, heat-treated, and shot-peened during production for precise rate accuracy and fatigue resistance.
• Tapered design with 3.5 in. upper I.D. and 2.5 in. lower I.D. fits QA1 Mustang II coil-over seats without adapters.
• Squared and ground ends ensure straight, consistent spring operation and accurate rate delivery.
• Chrome-plated finish provides a polished, show-quality appearance and corrosion protection.
• Lifetime guaranteed to remain within 2% of original free height and rate under normal operating conditions.

Specifications

• Spring Rate: 600 lbs./in.
• Free Length: 8 in. (203.2 mm)
• Upper I.D.: 3.5 in. (88.9 mm)
• Lower I.D.: 2.5 in. (63.5 mm)
• Spring Style: Tapered (Mustang II)
• Material: Chrome Silicon Steel (CrSi)
• Finish: Chrome Plated
• Progressive Rate: No (linear rate)
• Quantity: Sold Individually
• Shipping Weight: 5.42 lbs.

Included Components

• 1x Tapered Chrome Coil Spring (8 in., 600 lb./in.)

Product Description

The QA1 8MB600 is a tapered chrome silicon coil spring engineered for Mustang II independent front suspension coil-over conversion systems. With an 8 in. free length, 600 lb./in. linear rate, and a tapered profile measuring 3.5 in. at the upper seat and 2.5 in. at the lower seat, it fits directly into QA1 Mustang II Pro Coil coil-over kits without adapters or modification. Chrome silicon steel construction, combined with a cold winding, heat treating, and shot peening process, delivers a spring that holds its rate and free height with exceptional consistency - QA1 backs this with a lifetime guarantee to within 2% of the original free height and rate under normal use.

The 600 lb./in. rate is a popular choice for heavier-nosed builds including big block or LS-swapped hot rods, street rods, and classic trucks where the front end carries more weight. The polished chrome plated finish gives the spring a show-quality appearance that pairs well with exposed front suspension builds. This spring is sold individually - most Mustang II IFS setups require two. The 8MB series is also available in 400, 500, and 700 lb./in. rates to match a wide range of build weights and handling targets.