QA1 Pro Rear Weld-In Coil-Over System - Double Adjustable - 12" x 150 lb/in - 3" Tube - Aluminum
The QA1 DD501-12150 Pro Rear Weld-In Coil-Over System is the ultimate custom suspension upgrade for drag racing, street performance, and street rod builds using 3" rear axle tubes. This complete double-adjustable system features lightweight aluminum shocks with independent 18-position compression and 18-position rebound tuning (324 possible combinations), paired with 12" high-travel 150 lb/in springs for excellent weight transfer and consistent performance. The weld-in design allows precise installation and ride height adjustment for the perfect stance and handling balance.
Key Features
- Double Adjustable Shocks: Independent compression and rebound tuning with 18 clicks each (324 combinations)
- 150 lb/in Springs: Lightweight high-travel rate ideal for drag, street, and performance applications
- 12" Spring Length: Optimized for maximum travel and lowered setups
- 3" Tube Specific: Designed for weld-in on vehicles with 3" rear axle tubes
- Lightweight Aluminum Construction: Reduces unsprung weight for better performance
- Fully Rebuildable/Revalveable: Serviceable by QA1 or authorized centers
Specifications
| Specification | Detail |
|---|---|
| Part Number | DD501-12150 |
| Position | Rear Weld-In |
| Shock Type | Double Adjustable Aluminum |
| Spring Rate | 150 lb/in |
| Spring Length | 12" |
| Axle Tube Diameter | 3 inches |
| Application | Custom Drag, Street Performance & Street Rod Builds |
| Installation | Weld-In Coil-Over Conversion |
| Country of Origin | United States |
| Warranty | Limited Lifetime (QA1) |
| Shipping Weight | Approx. 25-35 lbs |
What's Included
- Pair of QA1 Double Adjustable Rear Coil-Over Shocks
- Pair of 12" x 150 lb/in High-Travel Springs
- All Mounting Hardware & Brackets for 3" Axle Tubes
- Detailed Installation Instructions
Product Notes
- Designed for weld-in installation on vehicles with 3" rear axle tubes
- 150 lb/in spring rate is a lighter rate suitable for drag racing and street performance builds
- Professional welding and alignment recommended
- May require driveline angle adjustments depending on application
Installation Notes
- Estimated time: 6-10 hours (welding required), advanced difficulty
- Weld-in system requires professional fabrication skills
- Full rear alignment and driveline angle check required after installation
This Part Fits
| Application | Notes |
|---|---|
| Custom Builds with 3" Rear Axle Tubes | Drag Racing, Street Performance, Street Rods – Weld-In |
Why Choose QA1 Pro Rear Weld-In Coil-Over System?
- Full double-adjustable control for perfect weight transfer and handling
- Lightweight aluminum shocks with high-travel springs for maximum performance
- Premium QA1 quality made in the USA with lifetime warranty confidence
Frequently Asked Questions
-
Q: Is this a bolt-on or weld-in kit?
A: This is a weld-in system designed for 3" rear axle tubes. -
Q: What spring rate is included?
A: 150 lb/in lighter rate ideal for drag and street performance applications. -
Q: What is the warranty?
A: Covered by QA1’s limited lifetime warranty.
Shipping & Handling
- Method: UPS / FedEx Ground
- Availability: In stock ships same or next business day
- Packaging: Secure protective packaging
- Weight: Approx. 25-35 lbs
Coilovers
Upgrade your vehicle with high-performance coilovers and coilover kits designed to improve handling, ride quality, and stance. We carry premium adjustable coilovers, suspension systems, and performance dampers for street, track, and off-road applications. Coilovers from Top Suspension Brands Shop industry-leading brands trusted by enthusiasts and professional builders, including FOX, Bilstein, ICON Vehicle Dynamics, QA1, Ridetech, Ohlins, Fabtech Dirt Logic, Silver's NEOMAX, and H&R. These brands are engineered for performance handling, durability, and precision suspension tuning across a wide range of vehicles. Performance Coilover Kits & Adjustable Suspension Our collection includes adjustable coilover kits with ride height and damping adjustment, front and rear coilover systems, coilover conversion kits, performance shocks and dampers, lift coilovers for trucks and SUVs, and lowering coilovers for street and track cars. Whether you're dialing in a track build, lowering yo...
View Coilovers Products
Coilovers & Components
Browse premium coilovers and suspension components including coilover kits, coilover shocks, coilover springs, lowering springs, shock hardware, suspension boots, dampening adjustment components, and performance suspension systems for trucks, SUVs, muscle cars, off-road builds, and street performance vehicles. Shop Top Coilover & Suspension Brands Find trusted suspension brands including Silver's NEOMAX, FOX, QA1, Eibach, ICON Vehicle Dynamics, Bilstein, KW Suspension, Ohlins, Ridetech, Fabtech, and ARB/OME. These brands are known for adjustable coilovers, performance shocks, lift and lowering suspension systems, coilover springs, and suspension hardware for daily driving, off-road use, drag racing, and track-focused builds. Coilovers & Components for Street, Track & Off-Road This collection includes complete coilover kits, front and rear coilovers, coilover springs, shock boots and protective covers, dampening adjustment extenders, suspension hardware kits, lowering spr...
View Coilovers & Components Products
QA1
Shop All QA1 Coilovers, Shocks, Springs, Handling Kits & Suspension Components Browse premium QA1 suspension parts and performance components at Black Ops Auto Works, including coilover kits, shock absorbers, lowering kits, handling kits, suspension conversion systems, four-link systems, springs, struts, rod ends, linkage rods, tube adapters, and suspension hardware for muscle cars, trucks, street builds, drag cars, and pro-touring applications. QA1 is one of the most recognized names in the suspension category, known for engineering products that improve ride quality, adjustability, handling, weight transfer, and overall vehicle control. Why Choose QA1 Suspension Products QA1 products are built for enthusiasts looking to improve suspension performance on classic, street, strip, and performance truck platforms. Popular reasons customers choose QA1 include: Adjustable suspension tuning for street and track use Improved handling, ride control, and weight transfer Vehicle-specific...
View QA1 Products
Suspension
Aftermarket suspension systems improve handling, ride quality, and ride height adjustment beyond what the factory suspension provides. From lowering springs and coilover kits for sport handling to lift kits and leveling kits for truck and SUV off-road capability, quality suspension components transform how a vehicle rides and handles. Popular Suspension Upgrades Popular suspension upgrades include coilover kits for adjustable ride height and damping, sport lowering springs for improved handling and reduced body roll, performance shock absorbers and strut assemblies, sway bar and end link upgrade kits, subframe brace kits, and complete suspension packages for lifted trucks and off-road SUVs. Alignment kits including camber bolts and camber arms are also frequently ordered after ride height changes. What is the difference between coilovers and lowering springs? Coilovers are complete shock and spring assemblies with adjustable ride height set by threading the spring perch on the shock...
View Suspension Products


