Spring Conventional 8.00in x 5in x 425lb

The Spring Conventional 8.00in x 5in x 425lb from SWIFT SPRINGS is a precision coil spring engineered for performance suspension tuning and custom vehicle builds. Whether you're lowering a street car, fine-tuning a track setup, or restoring a classic with modern handling characteristics, this conventional spring delivers the consistent rate and predictable behavior that experienced mechanics demand. At 425 pounds per inch (lb/in) spring rate, it strikes a balance between maintaining ride comfort on daily drivers and providing adequate support for moderate performance applications.

SWIFT SPRINGS conventional coils are manufactured using high-carbon spring steel, heat-treated to maintain consistent rate across the full compression range and resist fatigue over thousands of cycles. The 8-inch free length and 5-inch coil diameter make this spring suitable for various double-wishbone and MacPherson strut applications, while the 425 lb/in rate ensures linear force delivery without bind-up or instability. Unlike progressive springs that stiffen dramatically at compression, conventional springs offer predictable handling geometry—critical for drivers who demand responsive steering feedback and consistent body roll control during cornering.

This spring works best for front or rear suspension upgrades on street-performance vehicles, road-course builds, and vintage restorations requiring modern geometry. Pair it with quality dampers and proper ride-height geometry to unlock handling gains without sacrificing compliance on imperfect pavement. Always verify fitment against your specific vehicle platform and consult suspension geometry data before installation; incorrect spring rate or height can compromise alignment, tire wear, and braking stability. For DIY installers, professional alignment is mandatory after installation to ensure camber, caster, and toe specifications are met.