LQ4 Engine Guide: Specs, Upgrades, and Why It’s the Best LS Swap Engine
- Elvis Gonzalez
- Sep 22, 2025
- 4 min read
Updated: Sep 28, 2025
Learn everything about the GM LQ4 engine — specs, performance potential, and why it’s the best budget-friendly LS swap motor for boosted builds.
Introduction: Why the LQ4 Engine is a Top Pick
The GM LQ4 6.0L V8 engine is a powerhouse in the world of performance builds and LS swaps. Known for its strength, reliability, and affordability, the LQ4 is a favorite for car enthusiasts who want serious horsepower without breaking the bank.
Whether you’re upgrading a classic muscle car, boosting a modern street machine, or building a reliable truck motor, the LQ4 is one of the best budget LS engines available today.
What is the LQ4 Engine?
The LQ4 is a 6.0-liter Gen III LS-based V8 engine produced by General Motors from 1999 to 2007.Originally designed for heavy-duty trucks and SUVs, it’s built to handle demanding workloads, making it incredibly durable and upgrade-friendly.
Vehicles Equipped with the LQ4
Chevy Silverado 2500 & 3500
GMC Sierra 2500 & 3500
Chevrolet Suburban 2500
GMC Yukon XL 2500
Chevrolet Express Van
GMC Savana Van
Hummer H2
Pro Tip:Vans often have low-mileage LQ4s since they’re typically used for lighter-duty commercial work — perfect for finding a clean engine at a great price.
LQ4 Engine Specs
Spec | Details |
Displacement | 6.0L / 364 cubic inches |
Block Material | Cast Iron |
Bore x Stroke | 4.00" x 3.62" |
Compression Ratio | 9.4:1 |
Horsepower (Stock) | 300–325 HP |
Torque (Stock) | 360–370 lb-ft |
Cylinder Heads | Aluminum 317 Cathedral-Port |
Why 317 Heads Are Great for Boost
The 317 heads that come stock on the LQ4 have larger combustion chambers, lowering compression. This makes them ideal for turbo or supercharged setups, allowing you to safely run more boost without detonation.
Why the LQ4 is the Best LS Swap Engine
The LQ4’s popularity comes down to four major advantages:
1. Extreme Strength and Reliability
Iron block construction makes it more durable than aluminum LS blocks.
Can handle 700+ horsepower on stock internals with proper tuning.
Perfect for high-boost builds or heavy-duty performance applications.
2. Affordable and Widely Available
Found in millions of GM trucks and vans.
Junkyard pricing: Complete engines often sell between $800 – $1,500.
A cost-effective alternative to LS2 or LS3 engines.
3. Boost-Ready from the Factory
The 9.4:1 compression ratio is perfect for adding a turbocharger or supercharger.
Many builders run single turbo setups pushing 600+ HP on a stock bottom end.
4. Huge Aftermarket Support
Endless parts availability:
Camshaft upgrades
High-performance intakes
Swap kits and mounts
Standalone ECUs
You’ll never struggle to find performance upgrades or replacement parts.
LQ4 vs. LQ9: Key Differences
The LQ9 is another 6.0L LS engine often compared to the LQ4.Here’s how they stack up:
Feature | LQ4 | LQ9 |
Compression Ratio | 9.4:1 | 10.0:1 |
Stock Horsepower | 300–325 HP | 345 HP |
Best For | Turbo / Supercharged Builds | Naturally Aspirated Builds |
Bottom Line:Choose LQ4 if you’re adding boost.Choose LQ9 for naturally aspirated power.
How to Identify an LQ4 Engine
To make sure you’re getting a true LQ4, check the 8th digit of the donor vehicle’s VIN:
VIN Digit | Engine |
U | LQ4 |
N | LQ9 |
You can also check casting numbers on the engine block:
Common LQ4 castings: 12551358, 12573581, 12577184
LQ4 Upgrade Roadmap
Here’s a simple path to upgrading your LQ4 based on your goals:
Stage 1: Budget Performance (400–450 HP)
Truck cam swap or mild performance cam
Long-tube headers
Cold air intake
ECU tune
Stage 2: Boosted Build (600–800 HP)
Turbocharger or supercharger kit
ARP head studs
Upgraded fuel injectors and fuel pump
Professional dyno tune
Stage 3: Extreme Build (1,000+ HP)
Forged pistons and rods
Ported 317 heads or aftermarket heads
Twin turbo setup
Dual-fuel system
Best Vehicles for an LQ4 Swap
Because of its LS architecture, the LQ4 fits into countless projects.Popular swaps include:
Classic Muscle Cars (Chevelle, Camaro, Oldsmobile Cutlass Supreme 442)
Street Trucks (Chevy C10, Silverado performance builds)
Off-Road Vehicles (Rock crawlers, Jeeps, lifted trucks)
Restomod projects
Tip for Swaps:Use readily available LS swap kits to simplify mounting, wiring, and tuning.
Where to Find an LQ4 Engine
LQ4 engines are common in salvage yards and online marketplaces.Here’s what you can expect to pay:
Short Block: $500 – $800
Complete Engine: $800 – $1,500
Low-Mileage Pull-Out: $1,500 – $2,500
When buying, always:
Verify VIN digit = U (LQ4).
Check oil condition and run a compression test.
Inspect for cracks or damage on the block.
SEO Tips for Your Wix Catalog
If you’re adding LQ4 engines to your Wix inventory catalog:
Use SEO-friendly titles, like:“LQ4 6.0L V8 Engine for Sale – Perfect for LS Swap or Turbo Build”
Include keywords in descriptions:
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LQ4 swap motor
6.0 LS engine
boosted LS build
Add internal links:
Link to related parts: LS Swap Kits | Turbo Kits | Performance Cams
Use alt text on images like:“Used LQ4 6.0L engine for sale – GM LS swap ready”
Conclusion: Why Choose the LQ4
The LQ4 engine remains one of the best options for anyone looking to build a high-horsepower, budget-friendly project.With its strong iron block, low compression ratio, and massive aftermarket support, it’s perfect for turbo builds, street machines, and classic LS swaps.
Whether you’re restoring a classic, building a race truck, or just looking for reliable power, the LQ4 is a proven platform that delivers performance without draining your wallet.
Next Steps
Browse our Auto Parts Inventory to see if we have an LQ4 in stock.
Contact us for help sourcing engines, swap kits, or performance upgrades.
Subscribe to our blog for more LS engine tips and guides.
SEO-Optimized Keywords
Here are keywords naturally included throughout the blog to boost ranking:
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