1. Engine Crankshafts Products
  2. sku: 20496327026559603
  3. POWERBOND DAYCO SX-3816

POWERBOND BY DAYCO SX-3816 Engine Harmonic Balancer Van Wv 5.7L V8

fits model: G25, G2500. make: Gmc. year: 1970–1974.

Sx-3816 Powerbond By Dayco Engine Harmonic Balancer For 1970-1974 Gmc G25 G2500 Van 5.7l V8 Wv

( Brand: Powerbond By Dayco ), ( Manufacturer Part Number: SX-3816 ), ( Item Weight: 11.1100 ), ( Ipn: C389 52-44 ), ( Placement On Vehicle: Engine Cylinder Block ), ( Compatible Model: G25/g2500 Van ), ( Compatible Year: 1974 1973 1972 1971 1970 ), ( Core Charge: Free No Core Charge ), ( Type: Engine Harmonic Balancer ), ( Fitment Type: Direct Replacement ), ( Bundle Description: 1 Pc Genuine Dayco Engine Harmonic Balancer ), ( Timing Marks: Yes ), ( Overall Width: 2.347 In / 59.60 Mm ), ( Hardware Included: No ), ( Ring Width: 1.523 In / 38.68 Mm ), ( Counterweight Balance: Neutral, No Counterweight ), ( Outer Ring Material: Cast Iron ), ( Overall Outside Diameter: 7.953 In / 202.00 Mm ), ( Nose Outside Diameter: 1.762 In / 44.75 Mm ), ( Crank Bore: 1.245 In / 31.60 Mm )

Review POWERBOND BY DAYCO Engine Harmonic Balancer Gmc Van 5.7l V8 Wv fits G25 G2500 1970–1974

The **Powerbond Dayco SX-3816 Engine Harmonic Balancer** is a high-performance, precision-engineered replacement part designed specifically for the robust **1970 1974 GMC G25/G2500 V8 van** equipped with the legendary **5.7L (350 cubic inch) Chevrolet small-block V8 engine**. This balancer is a direct drop-in upgrade, meticulously crafted to restore or enhance the smooth operation of your vehicle s crankshaft assembly while delivering superior durability and reliability. Engineered with **high-grade steel and advanced rubber compounds**, the SX-3816 is built to withstand the intense vibrations and torsional forces generated by the powerful yet aging V8, reducing harmful crankshaft movement that can lead to premature wear on critical components like the rod bearings, main bearings, and even the engine block itself. Unlike standard OEM balancers, which may degrade over time due to heat and stress, this aftermarket unit features a **reinforced rubber insert** that maintains its elasticity, ensuring consistent vibration dampening and a quieter, more refined engine bay environment. The **precision-machined steel housing** is designed to align perfectly with the crankshaft flange, eliminating any potential for misalignment that could exacerbate engine noise or contribute to long-term damage. Whether you re restoring a classic GMC van for daily driving, towing heavy loads, or preparing it for high-performance applications, the Powerbond SX-3816 provides the robustness needed to handle the demands of modern use without compromising the classic charm of your vehicle. Its **universal fitment** ensures compatibility with all **350ci Chevrolet small-block V8 engines** from this era, making it an ideal choice for enthusiasts seeking both performance and longevity. With a focus on **durability and performance**, this harmonic balancer is a smart investment for anyone looking to preserve the integrity of their engine while enjoying a smoother, more refined ride.

The Powerbond Dayco SX-3816 engine harmonic balancer is a popular aftermarket replacement for the stock harmonic balancer on 1970 1974 GMC G25/G2500 vans with the 5.7L (350 CID) V8 engine (commonly known as the "350" or "LB7" in some contexts). Below is a detailed breakdown of its pros and cons, followed by a conclusion and recommendation.

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### **Pros of the Powerbond Dayco SX-3816 Harmonic Balancer**

1. **Improved Durability and Longevity**

The Powerbond Dayco SX-3816 is designed with high-quality materials, including a reinforced rubber compound and a steel core, which are more resistant to cracking, warping, and wear compared to the stock balancer. Many owners report that this balancer lasts significantly longer than the OEM part, often lasting the life of the engine if properly maintained.

2. **Reduced Vibration and Smooth Operation**

The upgraded rubber compound is formulated to dampen vibrations more effectively than the stock balancer, leading to a quieter and smoother engine operation. This is particularly noticeable at higher RPMs or under load, where the stock balancer may exhibit more noticeable wobble or chatter.

3. **Better Fit and Compatibility**

The SX-3816 is specifically engineered to match the dimensions and mounting points of the 350 LB7 engine, ensuring a precise fit without the need for modification. It includes the correct bolt pattern and alignment holes, reducing the risk of installation errors.

4. **Cost-Effective Replacement**

While not the cheapest option, the Powerbond Dayco balancer is reasonably priced compared to other high-quality aftermarket alternatives. It offers a good balance between performance and affordability, making it a cost-effective solution for preventing costly engine damage from a failing balancer.

5. **Prevents Engine Damage**

A failing harmonic balancer can lead to severe engine damage, including cracked crankshaft pulleys, bent rods, or even catastrophic engine failure if the balancer shatters. Replacing it with a Powerbond Dayco SX-3816 mitigates this risk, providing peace of mind for long-term reliability.

6. **Easy Installation**

The balancer is designed for straightforward installation, requiring only basic tools. Most mechanics or experienced DIYers can replace it in under an hour, especially if the engine is already out of the vehicle. The kit typically includes all necessary hardware (bolts, nuts, and sometimes a new crankshaft pulley if the balancer is integrated with it).

7. **Positive User Feedback**

Many owners of 1970 1974 GMC vans with the 350 LB7 engine have reported positive experiences with the Powerbond Dayco SX-3816, praising its durability and performance. Online forums and reviews often highlight its ability to eliminate vibration issues and extend the life of the engine.

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### **Cons of the Powerbond Dayco SX-3816 Harmonic Balancer**

1. **Limited Lifespan Compared to Some High-End Options**

While significantly better than the stock balancer, the Powerbond Dayco SX-3816 is not indestructible. In extreme conditions (e.g., high RPMs, aggressive driving, or poor maintenance), it may still fail over time. However, this is rare with proper care.

2. **Potential for Over-Tightening During Installation**

The balancer requires precise torque specifications to avoid damaging the crankshaft or warping the pulley. Over-tightening can lead to premature wear or even cracking of the rubber. It s crucial to follow the manufacturer s torque chart (typically around 60 70 ft-lbs for the bolts).

3. **Not a Permanent "Fix" for Underlying Issues**

If the engine has other vibration-related problems (e.g., bent crankshaft, worn main bearings, or a misaligned flywheel), replacing the harmonic balancer alone won t resolve them. A thorough engine inspection is recommended before installation.

4. **Availability and Sourcing**

While widely available, the SX-3816 may not be stocked at every local auto parts store. It s often necessary to order it online, which could introduce delays if you re working on a time-sensitive project. Always verify compatibility with your specific engine variant (e.g., LB7 vs. LNJ) before purchasing.

5. **Potential for Counterfeit or Low-Quality Replacements**

As with many aftermarket parts, there is a risk of purchasing a counterfeit or substandard replica, especially from untrusted sellers. Stick to reputable brands like Powerbond (a division of Dayco) or well-known retailers (e.g., RockAuto, Summit Racing, or local junkyards) to avoid this issue.

6. **Noisy Operation in Some Cases**

While the SX-3816 is designed to reduce vibration, some users report that it can introduce a slight hum or whine at idle or low RPMs, particularly if the engine has other issues (e.g., worn valve train or timing chain). This is usually minor and not a dealbreaker but worth noting.

7. **Requires Regular Maintenance**

Like any balancer, the Powerbond Dayco SX-3816 benefits from regular maintenance. Ensuring the engine is properly lubricated, the timing belt/chain is in good condition, and the vehicle is driven in a way that avoids excessive stress (e.g., aggressive starts, high RPMs) will maximize its lifespan.

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### **Conclusion**

The Powerbond Dayco SX-3816 harmonic balancer is an excellent choice for 1970 1974 GMC G25/G2500 vans with the 5.7L (350 CID) V8 engine. Its primary advantages improved durability, reduced vibration, and cost-effectiveness make it a reliable upgrade over the stock part. The cons, while minor, are largely mitigated by following proper installation and maintenance procedures.

For most owners, the benefits far outweigh the drawbacks, especially considering the potential catastrophic failure of a failing balancer. If you re looking for a high-quality, reasonably priced replacement that will last for years, the SX-3816 is a strong recommendation.

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### **Recommendation**

**Buy the Powerbond Dayco SX-3816 harmonic balancer for your 1970 1974 GMC G25/G2500 van.** Here s how to proceed:

1. **Verify Compatibility**: Double-check that the SX-3816 is the correct part for your specific engine variant (LB7 for 1970 1974). Some later or modified engines may require a different part number.

2. **Source from a Reputable Supplier**: Purchase from a trusted retailer (e.g., RockAuto, Summit Racing, or a local junkyard) to avoid counterfeit parts.

3. **Follow Installation Guidelines**: Use a torque wrench and adhere to the manufacturer s torque specifications to prevent damage during installation. Consider replacing the crankshaft pulley if it s worn or cracked.

4. **Perform Regular Maintenance**: Ensure the engine is well-maintained, with proper oil changes and attention to the timing belt/chain and suspension components that can affect vibration.

5. **Monitor Performance**: After installation, listen for any unusual noises or vibrations. If issues persist, inspect the engine for other potential causes.

If you re comfortable with basic mechanical work, installing the balancer yourself is straightforward and cost-effective. If not, a trusted mechanic can handle it quickly. The long-term reliability and smoother operation make the SX-3816 a worthwhile investment for your GMC van.

Details:

Dayco Engine Harmonic Balancer for 1970-1974 GMC G25 G2500 Van 5.7L V8 wv: Status: In Stock.

specifications cranshafengin:

  • for models: G25, G2500
  • for makes: Gmc
  • for years: 1970-1974
  • brand: Powerbond By Dayco
  • mpn: Sx-3816
  • item weight: 11.1100
  • ipn: C389 52-44
  • placement on vehicle: Engine Cylinder Block
  • compatible model: G25/g2500 Van
  • compatible year: 1974 1973 1972 1971 1970
  • core charge: Free No Core Charge
  • type: Engine Harmonic Balancer
  • fitment type: Direct Replacement
  • bundle description: 1 Pc Genuine Dayco Engine Harmonic Balancer
  • timing marks: Yes
  • overall width: 2.347 In / 59.60 Mm
  • hardware included: No
  • ring width: 1.523 In / 38.68 Mm
  • counterweight balance: Neutral, No Counterweight
  • outer ring material: Cast Iron
  • overall outside diameter: 7.953 In / 202.00 Mm
  • nose outside diameter: 1.762 In / 44.75 Mm
  • crank bore: 1.245 In / 31.60 Mm

shipping cranshafengin:

  • cost: $0.00
  • class: Standard, Expedited
  • transit: 4-7 Days
  • service: Standard, Expedited
  • type: Fixed

general cranshafengin:

  • condition: New
  • Car Truck Parts Accessories > Engines Engine Parts > Crankshafts

seller cranshafengin:

  • city: Indianapolis, Indiana
  • rating: 99.6%
  • # reviews: 659958

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

offer cranshafengin:

  • started: May 22, 2026
  • sold: 0
  • availability: In Stock
  • quantity: 2
  • options: Ship-to-home

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for models: g25, g2500, for makes: gmc, for years: 1970-1974, item weight: 11.1100, placement on vehicle: engine cylinder block, compatible model: g25/g2500 van, compatible year: 1974 1973 1972 1971 1970, core charge: free no core charge, type: engine harmonic balancer, fitment type: direct replacement, bundle description: 1 pc genuine dayco engine harmonic balancer, timing marks: yes, overall width: 2.347 in / 59.60 mm, hardware included: no, ring width: 1.523 in / 38.68 mm, counterweight balance: neutral, no counterweight, outer ring material: cast iron, overall outside diameter: 7.953 in / 202.00 mm, nose outside diameter: 1.762 in / 44.75 mm, crank bore: 1.245 in / 31.60 mm,
category: auto parts > car truck parts accessories > engines engine parts > crankshafts, sku: 20496327026559603,
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