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  3. GM 2191K27939058

GM 2191K27939058 Heads Iv Cylinder 799 243 5.3 4.8L

fits model: Ls2, Ls6.

2191k27939058 Oem 799 Heads Gm Ls2 Ls6 Gen Iii Iv Cylinder 243 5.3 4.8l

( Brand: Gm ), ( Manufacturer Part Number: 2191K27939058 ), ( Type: Cylinder Head ), ( Material: Aluminum ), ( Vintage Part: No )

Review GM Oem 799 Heads Gen Iv Cylinder 243 5.3 4.8l fits LS2 LS6

This product is a meticulously crafted, high-performance **Gen IV LS2 and LS6 cylinder head kit**, specifically designed for the legendary **GM LS-series engines**, including the **5.3L (243 cubic inch) and 4.8L variants** (part numbers **2191K27939058** and **799 heads**). Engineered for enthusiasts and professional mechanics alike, this kit represents the pinnacle of aftermarket cylinder head technology, blending precision engineering with the raw power potential of the LS platform. The **799 heads** are renowned for their aggressive porting, optimized combustion chambers, and robust construction, making them a favorite among builders seeking maximum horsepower and reliability. Whether you're restoring a classic LS2-based engine from the **C5 Corvette, Camaro SS, or Silverado SS**, or pushing the limits of an LS6 supercharged or turbocharged application, this kit delivers the foundation for a high-revving, high-torque powerplant. The **LS2 heads** (5.3L) are a slightly more refined take on the 799 design, offering a balance of flow and durability, while still providing substantial gains over stock components. Both head variants feature **high-quality castings** with **precision-machined intake and exhaust ports**, ensuring optimal airflow and combustion efficiency. The **intake ports** are generously sized to maximize fuel-air mixture velocity, while the **exhaust ports** are sculpted for efficient scavenging, reducing backpressure and improving exhaust flow. These heads are compatible with **LS-series engines** from **2006 to 2013**, including the **LS2 (5.3L), LS3 (6.2L), and LS6 (4.8L supercharged)**, making them a versatile choice for a wide range of applications. The kit includes **all necessary hardware**, including **high-strength bolts, gaskets, and seals**, ensuring a seamless installation process. For those seeking even greater performance, these heads pair exceptionally well with **high-flow intake manifolds, performance camshafts, and advanced ignition systems**, allowing for significant power increases without sacrificing reliability. Whether you're aiming for **street performance, drag racing, or high-RPM track use**, this cylinder head kit provides the structural integrity and airflow advantages needed to unlock the full potential of your LS engine. Built to withstand the stresses of aggressive tuning, these heads are a testament to the **LS platform s legendary durability**, even when pushed to extreme limits. With this kit, you re not just upgrading your engine you re investing in a **high-performance foundation** that will serve as the cornerstone of your next powerhouse build.

Here s a detailed breakdown of the pros and cons of purchasing a **GM LS2 (5.3L) and LS6 (4.8L) Gen IV V8 engines** (specifically the **2191K27939058** and **799 heads** variants) from a performance, reliability, and practicality standpoint, followed by a conclusion and recommendation.

---

### **Pros of the LS2 (5.3L) and LS6 (4.8L) Gen IV V8 Engines**

1. **Proven Performance and Reliability**

- The **LS2 (5.3L)** and **LS6 (4.8L)** are among the most robust Gen IV LS engines, designed for high-performance applications (e.g., Corvette, Camaro SS, and high-output truck applications).

- The **LS6** (4.8L) is a high-revving, high-output variant with a forged crankshaft, connecting rods, and pistons, making it ideal for forced induction builds.

- Both engines feature **cast-iron blocks** (LS2) and **aluminum blocks** (LS6), which are durable and resistant to warping compared to some modern aluminum blocks.

2. **Aftermarket Support and Modifiability**

- These engines have **extensive aftermarket support**, including high-flow heads, forged internals, and performance parts for both naturally aspirated (NA) and forced induction (FI) builds.

- The **LS2** is a great platform for **supercharging, turbocharging, or nitrous builds**, while the **LS6** is already optimized for high RPM (redline 6,800 RPM).

- **LS2 heads (799 series)** are known for their **good flow characteristics**, making them suitable for high-horsepower applications when paired with proper internals.

3. **Durability and Longevity**

- Both engines are **built to last** with proper maintenance. The **LS6 s forged internals** make it particularly resistant to catastrophic failure under extreme stress.

- The **LS2 s** cast-iron block is less prone to warping than some aluminum blocks, which can be an advantage in high-power applications.

- **Rod bolts** (on both engines) are **ARP-stud-friendly**, allowing for significant power increases without failure.

4. **Availability of Parts and Swappability**

- These engines are **widely available** in the aftermarket, with **rebuilt units, blueprints, and crate engines** from vendors like **LS Swap, Summit Racing, and JE Pistons**.

- They are **swappable into many GM and non-GM applications**, including trucks, SUVs, and even custom builds.

- **LS2 and LS6 parts** (heads, blocks, cranks, etc.) are **cheaper than some modern V8s** (e.g., Gen V LT1/LT4), making them cost-effective for high-performance builds.

5. **Fuel Efficiency (Relative to Power)**

- While not as efficient as modern turbocharged engines, the **LS2 (5.3L)** in a naturally aspirated form is **more fuel-efficient than a stock LS3 (6.2L)** in some cases, especially when tuned for performance.

- The **LS6 s high RPM** allows for **better throttle response** in high-RPM applications.

6. **Classic LS Engine Strengths**

- **Simple and robust design** with **fewer electronic quirks** compared to modern engines.

- **Easy to work on** with **bolted-on components** (no integrated modules like some modern engines).

- **Proven in racing** (NASCAR, NHRA, drag racing) for both NA and FI applications.

---

### **Cons of the LS2 (5.3L) and LS6 (4.8L) Gen IV V8 Engines**

1. **Thirst for Fuel and Oil**

- Both engines **consume oil** at a noticeable rate, especially under high-RPM or forced induction conditions. The **LS6 is worse** due to its high-revving nature.

- **Fuel economy suffers** compared to modern turbocharged engines (e.g., LT1, LT4). Even with tuning, they **won t match the efficiency of a turbocharged 5.0L or 3.0L twin-turbo V6**.

- **High octane fuel is recommended** for forced induction builds to prevent detonation.

2. **Maintenance Requirements**

- **Oil changes must be frequent** (every **3,000 5,000 miles** in performance applications) to prevent sludge buildup.

- **Timing chain stretch** is a known issue in some LS engines (though less common in the LS2/LS6 if maintained properly). **Chain tensioners and guides should be checked regularly**.

- **Head gasket failures** can occur if the engine is **overheated or improperly cooled**, though the **LS2 s cast-iron block helps mitigate this risk**.

3. **Weight and Size**

- Both engines are **heavy** ( 500 600 lbs with accessories), which can **negatively impact handling** in lightweight applications (e.g., sports cars).

- The **LS6 s aluminum block** is slightly lighter than the LS2 s cast-iron, but both are **bulkier than modern small-blocks** (e.g., Gen V LT1).

4. **Electronics and Tuning Complexity**

- While simpler than modern engines, **LS2/LS6 engines require proper tuning** for forced induction or high-power NA builds.

- **ECU flashing or standalone ECUs** (e.g., **Haltech, AEM, Link**) are often needed for **optimal performance**, adding cost.

- **Sensor failures** (e.g., MAF, crank, cam) can be more problematic than in modern engines with built-in diagnostics.

5. **Limited Modern Compatibility**

- Some **modern vehicles** (especially those with **direct injection or turbocharging**) may not be ideal platforms for LS2/LS6 swaps due to **cooling system differences, fuel system limitations, or emissions restrictions**.

- **OBD-II compliance** can be tricky if modifying for **street-legal use** in some regions.

6. **Cost of High-Performance Mods**

- While the **base engine is affordable**, **high-power builds** (e.g., **1,000 HP**) require **expensive upgrades**:

- **Forged internals** (crank, rods, pistons)

- **High-flow heads** (e.g., **JE, Edelbrock, LS2 heads with porting**)

- **Reinforced blocks** (if running extreme power)

- **Cooling upgrades** (radiator, oil cooler, intercooler for FI builds)

- **Supercharger/turbocharger systems** (e.g., **Eaton, Garrett, Paxton**) add significant cost.

7. **Potential for Overbuilding Without Proper Upgrades**

- **Stock LS2/LS6 blocks are not built for extreme power** (e.g., **1,500 HP**) without **reinforced blocks, rod bolts, and cooling upgrades**.

- **Rod bolt failure** is a real risk if **power is increased without proper internals**.

8. **Resale Value (Depreciation)**

- **Swapped LS engines** (especially in trucks/SUVs) **lose value quickly** compared to modern engines.

- **High-performance builds** (e.g., **LS2 supercharged, LS6 turbo**) may not retain value well unless they are **rare or highly modified**.

---

### **Comparison Between LS2 (5.3L) and LS6 (4.8L)**

**Factor** **LS2 (5.3L)** **LS6 (4.8L)**

-------------------------- ---------------------------------------- ----------------------------------------

**Stock Power** 310 350 HP (depending on app) 400 430 HP (high-RPM tuned)

**Redline** 6,000 RPM 6,800 RPM

**Block Material** Cast-iron Aluminum

**Internals** Cast pistons, steel crank/rods Forged pistons, forged crank/rods

**Best For** NA builds, supercharging, truck apps High-RPM NA, turbocharging, racing

**Oil Consumption** Moderate (worse at high RPM) Higher (due to high RPM)

**Cost (Base Engine)** $1,500 $2,500 (rebuilt) $2,000 $3,500 (rebuilt)

**Modifiability** Great for NA/FI, but needs internals Better for high-RPM builds

**Weight** 550 lbs 500 lbs

---

### **Conclusion and Recommendation**

#### **Who Should Buy an LS2 (5.3L) or LS6 (4.8L)?**

1. **Performance Enthusiasts Building a NA or FI Project**

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Details:

799 HEADS GM LS2 LS6 Gen III IV Cylinder Heads 243 OEM 5.3 4.8L: Tested and verified before removal,: Carefully packaged for safe delivery. Questions about fitment or condition. Trusted by thousands of fellow enthusiasts and builders. Motor sports Parts Graphics, Built by enthusiasts, for enthusiasts.

Motor sports Parts Graphics: M.P.G.

part #: 2191k27939058 price

  • $379.00

specifications cylinderheapar:

  • for models: Ls2, Ls6
  • brand: Gm
  • mpn: 2191k27939058
  • type: Cylinder Head
  • material: Aluminum
  • vintage part: No

offer cylinderheapar:

  • options: Ship-to-home
  • sold: 0
  • quantity: 1
  • best offers: True
  • availability: In Stock
  • started: June 3, 2026

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  • rating: 99.8%
  • city: Grafton, Wisconsin
  • # reviews: 2067

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  • Car Truck Parts Accessories > Engines Engine Parts > Cylinder Heads
  • condition: Used

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for models: ls2, ls6, type: cylinder head, vintage part: no,
category: auto parts > car truck parts accessories > engines engine parts > cylinder heads, material: aluminum, sku: 12244393909283892,
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