CHEVY 3817680 Block Power Pack Cylinder Heads Magnafluxed General 0.269 896

( Manufacturer Part Number: 3817680 ), ( Type: Cylinder Head Assembly ), ( Oe/oem Part Number: 3795896 ), ( Items Included: Valves, Springs, Keeper Assemblies, Rocker Arm Studs ), ( Material: Cast Iron ), ( Vintage Part: Yes ), ( Country Of Origin: United States )

Review CHEVY General Motors Corporation 0.269 896 Small block Power Pack Cylinder Heads Magnafluxed fits 283 327 1956–1967

This meticulously restored and thoroughly inspected **1956 1967 Chevrolet Small-Block Power Pack cylinder head set (3817680, 0.269" valve stem diameter, 896cc combustion chamber)** represents a rare and high-performance piece of classic American automotive engineering. Originally designed for the legendary **283 and 327 cubic-inch Small-Block Chevy engines**, these heads are a hallmark of the era s emphasis on simplicity, durability, and raw power. Crafted from high-quality cast iron with precision-machined passages, they feature the iconic **Power Pack design**, which includes a single-plane intake manifold port layout optimized for smooth airflow and efficient combustion. The **0.269" valve stem diameter** ensures compatibility with standard 1.625" intake and 1.5625" exhaust valves, allowing for a balanced valve train that maximizes horsepower while maintaining reliability a hallmark of Chevy s legendary small-block architecture.

Each head in this set has undergone **Magnaflux inspection**, a non-destructive testing process that reveals even the smallest cracks or internal defects, ensuring only the strongest, most structurally sound components make it into your engine. This meticulous quality control is critical for high-performance applications, where stress from forced induction, high RPM, or aggressive camshafts can quickly compromise weaker castings. The **896cc combustion chambers** strike an ideal balance between compression ratio potential and head gasket clearance, making these heads versatile for everything from mild street engines to high-performance builds. Whether you're restoring a classic Corvette, Camaro, or Nova, or building a modern hot rod, these heads deliver the timeless Chevy small-block performance you expect with the added assurance of a head set that has been vetted for peak structural integrity.

Beyond their mechanical prowess, these heads carry the heritage of an era when American muscle was defined by innovation and brute force. The **Power Pack designation** itself was a nod to Chevy s commitment to simplifying engine design while maximizing output, and these heads embody that philosophy perfectly. With their classic wedge-style combustion chambers, robust valve springs, and robust valve guides, they re built to handle the demands of modern modifications whether you re running a high-lift cam, a supercharger, or just pushing the limits of a naturally aspirated engine. For the enthusiast who values both authenticity and performance, this set of Magnafluxed cylinder heads is a must-have, offering a direct connection to the golden age of Chevy small-blocks while ensuring your engine runs with the same reliability and power it did in its prime.

### **Pros and Cons of Buying a 1956 1967 Chevrolet Small-Block (3817680, 0.269, 896, 283/327 Power Pack Cylinder Heads, Magnafluxed)**

#### **Pros**

1. **Classic Small-Block Chevy Engine**

- The 283/327 small-block Chevy is one of the most iconic and reliable engines ever produced. It has a proven track record of durability, performance, and aftermarket support.

- The **Power Pack cylinder heads** (with 0.269-inch valve seats) are a high-performance upgrade, offering better airflow and potential for increased horsepower compared to stock heads.

2. **Magnafluxed Engine**

- Magnaflux testing is a non-destructive method to check for cracks in the crankshaft, camshaft, and other critical components. If this engine passed Magnaflux, it suggests the iron parts are structurally sound, reducing the risk of catastrophic failure.

- A Magnafluxed engine is often a sign that the previous owner took care to inspect the internals before selling, which can be a good indicator of overall condition.

3. **896 (or 896A) Engine Code**

- The **896** designation typically refers to a **327 cubic inch small-block Chevy** with a **10.25:1 compression ratio** and **Power Pack heads** (or similar high-performance features). This engine is often considered a "hot rodder s engine" due to its balance of power and reliability.

- The **896A** variant (if applicable) may have additional modifications like a different camshaft or intake manifold, further enhancing performance.

- These engines are often found in **high-performance applications** (e.g., drag racing, street rods) and have a strong aftermarket following, meaning parts and tuning support are widely available.

4. **Potential for High Performance**

- With **Power Pack heads**, this engine can be tuned for **300 400 horsepower** with relatively modest modifications (e.g., carburetion upgrades, camshaft swaps, fuel system tweaks).

- The **283/327 small-block** is one of the most tunable engines ever made, with options ranging from **stock swaps** to **full nitrous or turbo setups**.

5. **Proven Reliability (When Maintained Properly)**

- Small-block Chevys are known for their **simplicity and robustness**. With proper maintenance (oil changes, valve adjustments, timing belt/crankshaft pulley checks), these engines can last **200,000 miles**.

- The **cast-iron block and heads** are durable, and the **pushrod design** is easy to work on compared to modern overhead-cam engines.

6. **Strong Aftermarket & Customization Options**

- **Performance parts** (cams, springs, intake manifolds, exhaust headers) are widely available and affordable.

- **Restoration and rebuild parts** (e.g., gaskets, seals, bearings) are easy to source.

- **Classic car community** is large, meaning **support groups, forums, and meetups** are abundant for troubleshooting and advice.

7. **Potential for Low Cost of Ownership (If Well-Maintained)**

- **Fuel efficiency** (for a V8) is decent expect **12 16 MPG** in a stock or mildly modified setup.

- **Repair costs** are low compared to modern engines, especially if you have basic mechanical skills.

- **Used parts** are cheap, and many mechanics are familiar with small-block Chevys.

8. **Nostalgia & Driving Experience**

- The **thump-thump-thump** of a small-block Chevy is a classic sound that many enthusiasts love.

- The **manual transmission option** (if available) provides a **more engaging driving experience** compared to modern automatics.

- Owning a **well-preserved 1956 1967 Chevy** (e.g., a Bel Air, Impala, or Corvette) adds **nostalgic value** beyond just the engine.

---

#### **Cons**

1. **Age and Wear**

- **1956 1967** is a **very old** engine design, and **wear is inevitable** after decades of use. Even if Magnafluxed, **valve guides, lifters, pushrods, and bearings** may need replacement.

- **Rod bearings and main bearings** can wear out, leading to **oil consumption or catastrophic failure** if not maintained.

2. **Potential for Hidden Issues**

- **Magnafluxing only checks for cracks**, not for **internal wear (e.g., rod bearing clearance, camshaft wear, or cylinder wall scoring)**.

- **Fuel system issues** (carburetor fouling, vacuum leaks) are common in older engines and can be **time-consuming to diagnose**.

- **Electrical problems** (ignition, wiring, gauges) are often **less reliable** than modern systems.

3. **Fuel and Emissions Concerns**

- **Lead-free fuel** can **corrode aluminum parts** (e.g., intake manifolds, valve covers) over time, leading to **leaks and failure**.

- **Modern emissions standards** may require **modifications** (e.g., EGR deletion, catalytic converter swaps) if the car is to be **street-legal in some areas**.

- **Ethanol fuel** can cause **rubber seals to swell and fail**, leading to **oil leaks**.

4. **Maintenance Requirements**

- **Valvetrain adjustments** (valve lash) must be done **every 5,000 10,000 miles** to prevent **mechanical wear**.

- **Oil changes** should be done **every 3,000 5,000 miles** (or more frequently if the engine is modified).

- **Timing belt/crankshaft pulley** (if equipped) must be replaced **every 50,000 60,000 miles** to prevent **catastrophic failure**.

- **Water pump and thermostat** failures are common and can lead to **overheating**.

5. **Potential for Poor Previous Maintenance**

- **Neglect** (e.g., no oil changes, seized lifters, blown head gaskets) is a **major risk** with older engines.

- **Oil leaks** (valve cover, oil pan, rear main seal).

- **Compression test results** (low compression can indicate **worn pistons, valves, or rings**).

- **Leak-down test** (to check for **burned valves or piston rings**).

- **History of modifications** (some aftermarket parts may not be compatible with stock components).

6. **Cost of Restoration**

- If the engine is **not in perfect condition**, a **full rebuild** (or at least a **major overhaul**) may be needed, which can cost **$2,000 $5,000 ** depending on parts and labor.

- **Cosmetic restoration** (bodywork, paint, interior) can be **expensive** if the car is heavily rusted or damaged.

7. **Reliability vs. Modern Standards**

- **No modern safety features** (airbags, ABS, modern electronics).

- **Poor fuel economy** compared to modern engines (even small modern V6s get better MPG).

- **Less refined** (vibration, noise, and rough idle are more noticeable than in modern cars).

8. **Insurance and Registration Challenges**

- **Classic car insurance** is **more expensive** than standard auto insurance.

- **Registration fees** for high-performance or modified engines may be **higher** in some states.

- **Smog checks** (in some areas) can be **difficult** if the engine is heavily modified.

9. **Market Value Depends on Condition**

- A **well-documented, restored, and maintained** 327 Power Pack engine will hold **better value** than one that s **neglected or unknown**.

- **Parts-only value** is decent, but **driveable/restorable value** varies widely.

10. **Time-Consuming to Work On**

- **No power steering or power brakes** (manual systems require more effort).

- **Manual transmissions** (if equipped) can be **fussy to drive** in stop-and-go traffic.

- **Diagnosing issues** (e.g., misfires, rough idle) can be **challenging** without proper tools.

---

### **Conclusion & Recommendation**

#### **Who Should Buy This Engine/Car?**

**Enthusiasts who enjoy working on cars** and don t mind **time-consuming maintenance**.

**Those who prioritize performance and sound** over modern convenience.

**Owners of classic cars** who want a **reliable, high-performance V8** for **drag racing, street rods, or weekend cru

Details:

No modifications are evident. Heads show no chipped corners/bosses or broken bolts. Intake valve diameter 1.72. Date codes C1962 03/19/62 D2562 04/25/62.

Exhaust valve diameter 1.50. Both have been magnaflux-tested with no cracks anywhere. I try to research everything list for accuracy, but amenity all-knowing and make mistakes, as do my resources ask that you understand what it is you re looking at before buying. Seats have no evidence of being changed.

Rocker studs are all straight and tight with no stripped threads. Matched set with casting number 3795896, equivalent to 3817680 3836842 - 3884520. Valves, springs and all keeper hardware have been removed bagged/tagged to original cylinders. Rocker arms are not included or available at this time.

part #: 3817680 prices

• $227.99-$445.00

specifications cylinderheapar:

• for models: 283, 327
• for makes: Chevy
• for years: 1956-1967
• mpn: 3817680
• type: Cylinder Head Assembly
• oe/oem part number: 3795896
• items included: Valves, Springs, Keeper Assemblies, Rocker Arm Studs
• material: Cast Iron
• vintage part: Yes
• country of origin: United States

general cylinderheapar:

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

offer cylinderheapar:

• best offers: True
• started: February 11, 2026
• availability: In Stock
• quantity: 1
• options: Ship-to-home
• sold: 0

returns cylinderheapar:

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

seller cylinderheapar:

• rating: 99.2%
• # reviews: 7848
• city: Franklin, Wisconsin

shipping cylinderheapar:

• service: Economy
• class: Economy
• transit: 3-8 Days
• type: Fixed
• cost: $100.00

payments cylinderheapar:

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

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