QA1 DD501-100V1 Pro-Rear Weld-In Coilover Kit Double Adjustable Proma Star 100/200 lb/in 3.25in Axle

The QA1 DD501-100V1 Pro-Rear Weld-In Coilover Kit is a complete rear suspension upgrade designed for drag racing, street performance, and street rod applications. This kit pairs double-adjustable Proma Star coilover shocks with variable-rate 100/200 lb/in springs and all necessary hardware for a full rear coilover conversion on vehicles with a 3.25-inch axle tube diameter.

The included double-adjustable Proma Star (DD501) shocks feature independent compression and rebound tuning, giving you precise control over your suspension at every stage. With 18 externally adjustable valve settings and evenly spaced valving changes, there are no abrupt jumps between clicks — just smooth, predictable tuning across the full adjustment range. The lightweight anodized aluminum shock bodies are built with a 5/8 in. centerless-ground chrome piston rod, PTFE-lined bearings, and aerospace-caliber sealing materials. All QA1 Proma Star shocks are dyno tested and eligible for an industry-leading Limited Lifetime Warranty.

Key Features:

• Double-adjustable independent compression and rebound valving (DD)
• 18 externally adjustable damping settings with no jumps between clicks
• Variable-rate 12-inch springs rated at 100/200 lb/in for progressive performance
• Designed for 3.25-inch diameter axle tubes
• Lightweight anodized aluminum shock body construction
• 5/8 in. centerless-ground chrome piston rod
• PTFE-lined bearings and aerospace-grade sealing materials
• Axle-mount bracketry, upper shock mounts, and weld-in tubing included
• Ride height adjustable in 3/4-inch increments via axle-mounted brackets
• Dyno tested for consistent performance and quality
• Made in the USA
• Eligible for QA1 Limited Lifetime Warranty (registration required)

This weld-in kit includes everything needed for installation: axle mount bracketry, upper shock mounts, weld-in crossmember tubing, coilover shocks, springs, and all necessary hardware. Commonly used in drag racing, street performance, and street rod builds, the DD501-100V1 delivers a proven, bolt-in solution for serious suspension upgrades.