Gen 4 Vortec 5.3ls LH6 Low Mileage Engine

Vortec 5.3 LS Engine for Sale | Gen 4 LH6 Low Mileage

If you are looking for a Vortec 5.3 LS engine for sale, the Gen 4 LH6 is one of the strongest used options available in the market right now. It is the most advanced naturally aspirated version of the Vortec 5.3 platform before GM moved to direct injection with the Gen 5 EcoTec3 family. As a result, low-mileage LH6 units from verified donor vehicles stay in constant demand for both direct factory replacements and LS swap projects.

At 53LSEngine.com, we carry low-mileage Gen 4 Vortec 5.3 LH6 engines. We inspect and compression test every unit before listing it. In addition, every engine comes with documented mileage from donor vehicle records, so you know exactly what you are buying before you commit.

What Is the Gen 4 Vortec 5.3 LH6 Engine

The LH6 is a Gen 4 5.3L LS engine that GM produced from approximately 2005 through 2013. It sits between the older Gen 3 LM7 and the newer Gen 5 EcoTec3 in the 5.3 LS family timeline. The Gen 4 generation brought meaningful improvements over the Gen 3, including dual independent variable valve timing, which GM calls VVT, and in some configurations Active Fuel Management cylinder deactivation, known as AFM.

Variable valve timing lets the engine management system adjust camshaft timing continuously based on load and RPM. As a result, you get improved low-end torque, better fuel economy at cruise, and stronger top-end output than a fixed-timing Gen 3 unit of the same displacement. For a factory replacement, this means the LH6 restores your vehicle to the performance and efficiency specification it was built around.

The LH6 also uses a port fuel injection system rather than the direct injection system in the Gen 5 EcoTec3. Because of that, it is significantly more swap-friendly than the newer generation. The fuel system requirements stay simpler, and the swap community already supports the ECU solutions well.

Gen 4 LH6 Specifications

Output figures vary by application and model year. Therefore, confirm your specific application before ordering.

What Vehicles Use the Gen 4 Vortec 5.3 LH6

GM installed the LH6 in a range of full-size truck and SUV applications across the 2005 to 2013 production window.

• Chevrolet Silverado 1500 — 2007 through 2013 in 5.3L configuration
• GMC Sierra 1500 — 2007 through 2013 in 5.3L configuration
• Chevrolet Tahoe — 2007 through 2013
• Chevrolet Suburban — 2007 through 2013
• GMC Yukon and Yukon XL — 2007 through 2013
• Cadillac Escalade — select configurations, so confirm your VIN before ordering

If your vehicle falls within this range, provide your VIN when you contact us. We then confirm the correct variant and configuration for your specific application before anything ships.

For Gen 3 applications from 1999 through 2007, see our Gen 3 Vortec 5.3 LS LM7 engine. For 2014 and newer applications, see our Gen 5 EcoTec3 5.3 LS L83 and L86.

Why Choose a Low Mileage Gen 4 LH6

The LH6’s combination of features makes it a strong choice for both direct replacement and swap applications.

Port Injection Makes Swaps Simpler

Unlike the Gen 5 EcoTec3, which uses direct injection, the LH6 runs sequential port fuel injection. This matters for swap builders because port injection fuel systems stay straightforward to plan. Existing ECU and wiring solutions also support them well. Since you do not need to engineer a high-pressure direct injection fuel supply, swap complexity and cost drop significantly compared to a Gen 5 unit.

Variable Valve Timing Improves Real-World Performance

The dual independent VVT system gives the engine management system control over both intake and exhaust cam timing independently. As a result, the LH6 delivers a stronger torque curve than the Gen 3 LM7 at the same displacement. For a factory replacement, this restores fuel economy and drivability. For swap builders, it also gives you a more capable naturally aspirated foundation before any modifications.

Aluminum Block Reduces Weight

The LH6 uses an aluminum block rather than the cast iron block found in some other 5.3 LS variants. Because of that, it cuts front-end weight compared to an iron block alternative. This helps in both factory applications and swap builds where weight distribution matters.

AFM Consideration

Some LH6 units carry Active Fuel Management. AFM remains a known wear consideration on higher-mileage Gen 4 units. For that reason, we document AFM system condition on every LH6 we list. Many swap builders and replacement buyers also delete AFM at installation using a delete kit and a calibration update. If you plan to delete AFM, let us know when you contact us. We then factor that into our unit recommendation.

What Is Included

Included components vary by unit. Contact us to confirm exactly what ships with the specific LH6 in current inventory.

Typically Included

• Complete LH6 long block assembly
• Intake manifold
• Fuel rails and injectors
• Valve covers
• Oil pan
• VVT actuators and solenoids
• Timing cover

Available on Select Units or Upon Request

• Engine wiring harness
• ECU and PCM
• Throttle body and sensors
• Front accessory drive components
• Coil packs and ignition components

Not Included Unless Confirmed

• Transmission
• Flywheel or flexplate
• Engine mounts
• Exhaust manifolds

Always confirm the complete component list with us before ordering. A long block and a complete engine package are different purchases at different price points.

Inspection and Testing

Every Gen 4 Vortec 5.3 LH6 we list goes through a documented inspection before it reaches the listing.

• Compression testing — We compression test all eight cylinders and record the actual readings. Then we give you those numbers before you purchase, not after.
• Oil condition assessment — We drain the engine oil and inspect it for metal contamination. Because visible metal particles point to internal wear, those units do not make the listing.
• VVT system inspection — We check the VVT actuators and solenoids for condition and connector integrity.
• AFM system documentation — We document AFM system condition separately on equipped units before shipping.
• Mileage verification — We verify mileage from donor vehicle records rather than estimating it.
• Audible assessment — We confirm no knocking, ticking, or unusual engine noise before packaging.

Other 5.3 LS Engine Options

Not sure the Gen 4 LH6 fits your build? Browse our other options instead.

• Gen 3 Vortec 5.3 LS LM7 — suits 1999 to 2007 applications and the simplest LS swaps
• Gen 5 EcoTec3 5.3 LS L83 and L86 — suits 2014 and newer applications with direct injection
• 5.3 LS Stage 3 Performance Build — built 5.3 LS for performance street and swap builds
• 525 HP Chevrolet Performance LS3 Crate Engine — factory GM Performance unit for high-output builds
• 510 to 560 HP Pro Built Complete Crate Engine — maximum output package for dedicated performance builds
• Browse all used 5.3 LS engines
• Browse junkyard 5.3 LS engines
• Browse build 5.3 LS engines

Pricing and Availability

We price Gen 4 Vortec 5.3 LH6 engines based on mileage, condition, included components, and current availability. Used units from verified donor vehicles with documented inspection typically fall within our standard used 5.3 LS engine pricing range.

Contact us at +1 (216) 230-5433 or Sales@53lsengine.com for current pricing, exact mileage, AFM configuration, included components, and availability on the specific unit in stock. In short, we give you every detail before you commit to anything.

Before you order, also review our refund and return policy so you understand the full terms. You can visit our About page to learn more about how we operate, and read our Privacy Policy to see how we handle your information.