QA1 DS501-2001 HD Pro Rear Weld-In Coilover Conversion Kit, Single Adjustable, 200 lb/in, 3.25" Axle

The QA1 DS501-2001 HD Pro Rear Coilover Conversion System is a complete weld-in coilover kit engineered to add fully adjustable rear coilover suspension to custom, street performance, and race vehicles equipped with 3.25-inch axle tubes. Designed for vehicles with a rear axle weight between 1,700 and 2,600 lbs, this kit delivers everything needed for a clean, professional installation without excess fabrication.

At the heart of the system are two QA1 Proma Star DS501 single-adjustable twin-tube coilover shocks, featuring a threaded aluminum body with clear anodized finish. A single adjustment knob provides 18 distinct valving positions, simultaneously tuning both compression and rebound damping for total ride control from one convenient location. The shocks are paired with 200 lb/in linear rate springs sized for optimal performance in this application.

Key Features:

• Designed for 3.25" diameter rear axle tubes
• Suitable for vehicles with 1,700–2,600 lb rear axle weight
• Single-adjustable Proma Star DS501 twin-tube coilover shocks — 18 valving positions
• 200 lb/in linear rate coilover springs included
• Double shear axle-mount bracketry for maximum strength
• Axle-mounted brackets provide ride height adjustment in ¾" increments
• Up to 9" of total ride height adjustability
• Includes 1-5/8" O.D. x .095 wall x 40" long weld-in upper shock mount tube
• All mounting hardware and bracketry included
• Shocks are 100% dyno tested, revalveable, and rebuildable
• Proudly made in Lakeville, Minnesota, USA

What's Included:

• (2) QA1 Proma Star DS501 single-adjustable coilover shocks
• (2) 200 lb/in coilover springs
• (1) 40" weld-in upper shock mount tube (1-5/8" O.D. x .095 wall)
• All axle brackets, tabs, and mounting hardware

Installation requires welding. A QA1 spanner wrench (P/N T114W or T115W, sold separately) is required for ride height adjustments. QA1 Proma Star shocks are eligible for a Limited Lifetime Warranty — register at QA1.net/warranty before installation.