GENUINE GM PARTS 12655430 Engine Cylinder Head

( Brand: Genuine Gm Parts ), ( Manufacturer Part Number: 12655430 ), ( Manufacturer Warranty: 1 Year ), ( Core Charge: 75.00 Which Is Included In The Total Price ), ( Type: Engine Cylinder Head Assembly )

Review GENUINE GM PARTS Canada Engine Cylinder Head Assembly

The **GM 12655430 Engine Cylinder Head** is a precision-engineered component designed specifically for select General Motors (GM) small-block V8 and high-performance applications, including models like the 5.0L (302 cubic inch) and 5.7L (350 cubic inch) LS-series engines. Crafted from high-grade cast iron or aluminum (depending on the variant), this cylinder head is built to deliver exceptional durability, thermal efficiency, and performance under demanding conditions. The head features a robust valve train system, incorporating hardened steel valves and high-quality valve springs that ensure reliable operation and minimize wear over extended use. The combustion chamber design is optimized for improved airflow and combustion efficiency, contributing to better horsepower and torque output while maintaining optimal fuel economy. The head is equipped with a dual-valve spring system on the exhaust side to reduce valve float at high RPMs, making it ideal for both street and track applications. Additionally, the integrated cooling passages and precise porting enhance heat dissipation, reducing the risk of overheating and prolonging the lifespan of the engine. Whether used in stock applications, modified setups, or high-performance builds, the GM 12655430 cylinder head is engineered to meet the rigorous demands of modern automotive engineering, ensuring consistent performance and reliability across a wide range of driving conditions.

### **Pros and Cons of Buying a GM 12655430 Engine Cylinder Head**

The **GM 12655430** is a cylinder head used in various General Motors engines, including the **LS1, LS2, and LS3** families. Below is a detailed analysis of its advantages and drawbacks.

---

### **Pros**

1. **High Performance and Reliability**

The GM 12655430 is designed for high-performance applications, featuring **forged internals, high-flow ports, and robust valve springs**. This makes it suitable for both stock and modified engines, including forced induction builds. Many users report **long-term durability** when properly maintained.

2. **Aftermarket Support and Availability**

This head is widely used in the performance market, meaning **aftermarket parts (valves, springs, retainers, gaskets, and studs) are readily available**. There are also **aftermarket machining services** (porting, polishing, and valve jobbing) that can enhance performance further.

3. **Compatibility with Common Modifications**

The head works well with **turbocharging, supercharging, and nitrous oxide (N2O) setups** when paired with the right supporting components (e.g., **reinforced rocker arms, upgraded lifters, and cooling solutions**). Many tuners recommend it for **high-RPM applications** due to its strong valve train.

4. **Resale and Swap Market Value**

Since these heads are popular in **LS engine swaps and high-performance builds**, they hold **good resale value** if kept in good condition. Many enthusiasts seek them for **restoration or upgrade projects**.

5. **Proven Durability in Extreme Conditions**

When properly maintained (correct oil viscosity, cooling, and timing), the **12655430 head has been known to last over 100,000 miles** in stock or mildly modified applications. Some high-performance builds exceed **200,000 miles** with proper care.

6. **Easier to Modify Than OEM Heads**

Unlike some factory heads, the **12655430 is often easier to machine and modify** due to its **forged construction and standard bolt patterns**. This allows for **custom porting, valve seat machining, and head stud upgrades** without major structural concerns.

7. **Used in Racing and Time Attack Applications**

Many **drag racing, time attack, and street racing builds** use this head due to its **strong valve springs and ability to handle high RPMs**. Some tuners recommend it for **forced induction setups** where stock heads would fail.

---

### **Cons**

1. **Higher Upfront Cost**

The **12655430 is more expensive than stock OEM heads** (often **$300 $800 depending on condition**). This can be a significant investment, especially for budget-conscious builders.

2. **Requires Proper Installation and Break-In**

Unlike stock heads, the **12655430 demands precise installation** (correct torque specs, gasket surface prep, and stud replacement if needed). Improper installation can lead to **leaks, warping, or even catastrophic failure**. A **professional machine shop or experienced mechanic** is often recommended.

3. **Maintenance Intensive**

- **Valve adjustments** (if using mechanical lifters) must be checked regularly.

- **Oil changes must use high-quality oil** (5W-40 or synthetic) to prevent sludge buildup.

- **Cooling system must be robust** (larger radiator, upgraded water pump) to prevent overheating under stress.

4. **Potential for Warping if Not Handled Correctly**

The **forged aluminum construction** means the head is **susceptible to warping** if not installed properly or if the engine overheats. This can lead to **leaking gaskets, poor sealing, or even cracked heads** in extreme cases.

5. **Not Always Directly Compatible with Stock Engines**

While it fits many **LS1/2/3 engines**, some **minor modifications may be needed** (e.g., **valve cover, intake manifold, or exhaust manifold swaps**). This adds to the **time and cost** of integration.

6. **Risk of Counterfeit or Poor-Quality Used Parts**

The aftermarket for these heads is **flooded with used and aftermarket options**, some of which may be **mismatched, cracked, or improperly machined**. Buyers must **inspect thoroughly** or purchase from **reputable sellers** to avoid issues.

7. **Requires Supporting Upgrades for Forced Induction**

If used with **turbocharging or supercharging**, the head **must be paired with reinforced components** (e.g., **stiffer rocker arms, upgraded lifters, and cooling solutions**). Without these, **valve float, excessive heat, or failure** can occur.

8. **Limited Stock Availability**

Since these heads are **high-performance parts**, **stock OEM replacements are rare** in the aftermarket. Buyers often must **source from junkyards, auctions, or specialty suppliers**, which can be time-consuming.

---

### **Conclusion**

The **GM 12655430 cylinder head** is a **premium choice for high-performance LS engine builds**, offering **superior durability, aftermarket support, and compatibility with forced induction**. However, it comes with **higher costs, stricter installation requirements, and increased maintenance needs** compared to stock heads.

**If you are building a high-RPM, turbocharged, or nitrous-equipped engine**, this head is an **excellent investment** that will outlast stock components. **If you are on a tight budget or building a mild street engine**, a **stock or lightly modified head** may be a more practical choice.

---

### **Final Recommendation**

- You are **building a high-performance or forced induction engine**.

- You **plan to modify the head (porting, valve jobbing, or upgrading components)**.

- You **have access to proper installation and maintenance** (or are willing to pay for professional help).

- You **want long-term reliability** in extreme conditions.

- You are **working with a limited budget** and can use a stock or aftermarket head instead.

- You **lack experience** in high-performance engine builds.

- You **cannot ensure proper cooling and oil maintenance**.

- You **do not need the extra performance** and a stock head will suffice.

- **Inspect thoroughly** before purchasing (check for cracks, warping, and proper machining).

- **Replace head gaskets, studs, and bolts** if the head is used.

- **Consult a mechanic or tuner** before installation to ensure compatibility with your build.

- **Use high-quality oil and maintain proper cooling** to maximize longevity.

For most **serious performance builds**, the **12655430 is a worthwhile upgrade** just ensure you are prepared for the **additional costs and responsibilities** that come with it.

Details:

Found a Better Price. Just Didn't Like it. See below for instructions. Return Core paid by: Buyer.

Genuine New OEM Parts. Return Core as: Money Back. 12655430: Genuine GM Parts: GENUINE PARTS CANADA 12655430 Engine Cylinder Head Assembly. This part fits vehicles made in the follow ING years 2017 ,2018.

Changed My Mind. Add details like Tried to install this part, and it didn't fit. Request a Return. High-value items are usually sent with signature-delivery requirements. If you do, our experts will hand-verify compatibility before shipping.

part #: 12655430 price

• $6194.29

specifications cylinderheapar:

• brand: Genuine Gm Parts
• mpn: 12655430
• manufacturer warranty: 1 Year
• core charge: 75.00 Which Is Included In The Total Price
• type: Engine Cylinder Head Assembly

seller cylinderheapar:

• rating: 99.2%
• # reviews: 19124
• city: Garland, Texas

payments cylinderheapar:

• credit card: Mastercard
• wallet: Google-pay
• other

offer cylinderheapar:

• availability: In Stock
• sold: 0
• options: Ship-to-home
• quantity: 5
• started: May 16, 2026

returns cylinderheapar:

• policy: Returns Accepted
• time: 30 Days
• paid by: Seller

shipping cylinderheapar:

• transit: 18-28 Days
• type: Fixed
• cost: $0.00
• class: Standard
• service: Standard

general cylinderheapar:

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

Genuine Gm Parts 12655430 Is Similar To:

• 10000187 General Motors Nos Gm Chevrolet Buick Oldsmobile Pontiac Engine Gasket (31.2% similar) You are buying on exactly what is pictured. Please also listings for thousands more nos Parts available immediate purchase. Nos stripes, decals, electrical and mechanical Parts important. When you homepage just enter the year, make and or model of your vehicle in search bar. These are very rare to ...(April 4th, 2018)
• 10101140 Gm Chevy Pair Of Matching Numbers Cylinder Heads Oval Ports (44.6% similar) For sale is this pair of Gm matching numbers cylinder heads. Oval ports, some surface rust Gm 1 will work on Chevy motors...(November 29th, 2018)
• 10118604 General Motors Nos Gm Chevrolet Buick Oldsmobile Pontiac Cadillac Head (31.2% similar) The part number is group. If you are out of the country please understand this while buying on item. Nos stripes, decals, electrical and mechanical Parts important. Please also listings for thousands more nos Parts available immediate purchase. When you homepage just enter the year, make and or ...(April 6th, 2018)
• 5 10127413 Head Bolts Oem Gm Lot Nos (24.5% similar) Out of a local estate...(March 26th, 2015)
• 10141913 General Motors Nos Gm Chevrolet Gmc Oldsmobile Truck Suv Head (28.8% similar) I do guarantee them to be nos or as otherwise described in my offer. Nos stripes, decals, electrical and mechanical Parts important. When you homepage just enter the year, make and or model of your vehicle in search bar I if are out country please understand this while buying on item. You are buying...(April 5th, 2018)
• 10149600 General Motors Nos Gm Chevrolet Gmc Truck Suv Diesel Cylinder (28.8% similar) 2j diesel V81990 1991 Chevrolet blazer and GMC jimmy model's with nos stripes, decals, electrical and mechanical Parts important. This means if the item is lost or damaged while in transit there no coverage. I do guarantee them to be nos or as otherwise described in my offer. This is a new old ...(February 14th, 2019)
• 350 V8 Mercruiser 10239906 5.7 Cylinder Vortec Gm Head Omc (35% similar) Vortex 7 v8 used cylinder head good working condition...(March 31st, 2015)
• 11569648 Gm Cylinder Head Bolt Lot Of Chevy Buick Olds Pontiac (32.3% similar) God bless the USA and her troops. Sales and shipping within the USA only. The winning bidder will receive all 10 pieces. They're nos in the original packaging. I do not know any of the exact applications. Please visit my other offer offerings for more quality stuff. Offered is a believed to fit some...(January 2nd, 2019)
• 1192 Bs Gm Nos Pair Set Head (31.1% similar) This listing is for the following item part item for sale is one pair 2 ea original nos pair set head gaskets part number victor 1192 BS part application Oldsmobile 330 condition very good new old stock feel free to contact me with questions or concerns...(December 15th, 2016)
• 1193743 Buick Skylark Special Nos Gm Alum Cylinder Head (35.9% similar) Buick skylark and special nos Gm 215 v8 alum cylinder head. Sorry-no valves or springs. Nice shape casting in Gm box. Fossick automotive products inc. Warning: cancer and reproductive harm...(March 15th, 2019)
• Head Lot 4 Oem Nos Bolts Cylinder 12338010 Gm (31.8% similar) Out of a local estate...(March 26th, 2015)