1. Engine Crankshafts Products
  2. sku: 19110151817797603
  3. POWERBOND DAYCO SX-1187

POWERBOND BY DAYCO SX-1187 Engine Harmonic Balancer Ol 6.5L 6.6L 7.0L

fits model: Impala. make: Chevrolet. year: 1966–1972.

Sx-1187 Powerbond By Dayco Engine Harmonic Balancer For 1966-1972 Chevrolet Impala 6.5l 6.6l 7.0l Ol

( Brand: Powerbond By Dayco ), ( Manufacturer Part Number: SX-1187 ), ( Item Weight: 10.0700 ), ( Ipn: C674 25-35 ), ( Placement On Vehicle: Engine Cylinder Block ), ( Compatible Year: 1972 1971 1970 1969 1968 1967 1966 ), ( 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: 2.686 In / 68.20 Mm ), ( Hardware Included: No ), ( Ring Width: 1.378 In / 34.98 Mm ), ( Counterweight Balance: Neutral, No Counterweight ), ( Outer Ring Material: Steel ), ( Overall Outside Diameter: 6.979 In / 177.25 Mm ), ( Nose Outside Diameter: 2.333 In / 59.25 Mm ), ( Crank Bore: 1.599 In / 40.60 Mm )

Review POWERBOND BY DAYCO Engine Harmonic Balancer Chevrolet 6.5l 6.6l 7.0l Ol fits IMPALA 1966–1972

The **Powerbond Dayco SX-1187 Engine Harmonic Balancer** is a premium, high-performance replacement part meticulously engineered to restore optimal vibration damping and drivability to your **1966 1972 Chevrolet Impala** equipped with the legendary **6.5L, 6.6L, or 7.0L inline-six "Big Block" engine**. Designed as an exacting upgrade over the stock rubber-mounted harmonic balancer, this unit combines **superior durability, precise balancing, and enhanced torsional rigidity** to eliminate excessive engine shake, reduce wear on critical components, and deliver a smoother, more refined power delivery especially under heavy loads or at higher RPMs. Crafted from **high-strength steel** and reinforced with **Dayco s proprietary SX (Super X) rubber compound**, this balancer is engineered to withstand the demanding torque and heat generated by your truck s robust inline-six, providing long-lasting performance without the flex or fatigue that plagues inferior aftermarket alternatives. The **precision-machined pulley** ensures flawless alignment with your serpentine belt system, while the **integrated vibration-dampening core** effectively isolates engine harmonics, reducing transmission shudder, drivetrain strain, and even premature wear on the crankshaft and connecting rods. Whether you re hauling heavy loads, towing trailers, or simply seeking a quieter, more responsive ride, the SX-1187 delivers a noticeable improvement in both **performance and reliability**, making it an indispensable upgrade for enthusiasts and fleet operators alike. Backed by **Dayco s reputation for quality** and compatible with OEM mounting hardware, this balancer is the ideal choice for restoring confidence in your classic Impala s powerplant while future-proofing it against the stresses of daily driving or off-road adventures.

### **Pros and Cons of Buying a Powerbond Dayco SX-1187 Engine Harmonic Balancer for a 1966 1972 Chevrolet Impala (6.5L, 6.6L, 7.0L Big Block)**

#### **Pros:**

1. **High-Quality Material** The Powerbond/Dayco SX-1187 is made from high-strength steel, which is more durable than standard rubber or polyurethane balancers. This reduces the risk of cracking or failure over time, especially under heavy loads or high RPM.

2. **Better Vibration Damping** Unlike basic rubber or polyurethane balancers, this unit features a **Powerbond** composite material that provides superior vibration isolation. This helps reduce engine shake, smooths out rough idle, and improves drivability, particularly in high-performance or modified engines.

3. **Longer Lifespan** The reinforced construction means this balancer is less likely to wear out prematurely, making it a cost-effective choice for long-term use, especially in classic trucks or high-mileage vehicles.

4. **Compatibility** The SX-1187 is specifically designed for the **6.5L, 6.6L, and 7.0L Chevrolet big-block engines** (including the Impala) from 1966 1972. It fits correctly without modification, reducing installation hassles.

5. **Reduced Engine Strain** By absorbing more vibration, the balancer helps reduce stress on the crankshaft, connecting rods, and other drivetrain components, potentially extending the life of the engine.

6. **Performance Benefits** If your engine is modified (turbocharged, supercharged, or high-performance camshafts), this balancer helps prevent excessive vibration that could damage internal components.

7. **Warranty & Reliability** Dayco is a well-known manufacturer with a reputation for durability. While warranties vary, a quality balancer like this should last the life of the engine if properly installed.

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#### **Cons:**

1. **Higher Upfront Cost** Compared to basic rubber or polyurethane balancers, the Powerbond/Dayco SX-1187 is more expensive. For a stock, lightly used engine, a cheaper balancer might suffice.

2. **Installation Requires Care** If not installed correctly, even a high-quality balancer can fail. Proper alignment with the crankshaft keyway and secure bolting are critical. Improper installation can lead to premature wear or damage.

3. **Not a Permanent Fix for Engine Issues** If your engine has severe internal problems (worn bearings, cracked blocks, or excessive endplay), replacing just the balancer won t solve those issues. A full engine inspection may still be needed.

4. **Weight Consideration** The steel construction is heavier than rubber or polyurethane, which could slightly affect engine harmonics in very high-performance applications (though the difference is minimal).

5. **Limited Availability of Replacement Parts** While Dayco is reliable, if the balancer fails, finding an exact replacement may be easier than sourcing aftermarket alternatives in some regions.

6. **Potential for Overkill on Stock Engines** If your engine is stock and runs smoothly, upgrading to a Powerbond balancer may not provide noticeable benefits beyond what a standard balancer offers.

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### **Conclusion & Recommendation**

The **Powerbond Dayco SX-1187 harmonic balancer** is an excellent choice for **1966 1972 Chevrolet Impala owners** with **6.5L, 6.6L, or 7.0L big-block engines**, especially if:

- The engine is **modified, turbocharged, or supercharged** (where vibration control is critical).

- You want **long-term reliability** and are willing to invest in a high-quality component.

- Your engine exhibits **excessive vibration, rough idle, or harmonic issues** that a standard balancer cannot resolve.

- You plan to **keep the vehicle for many years** and want to prevent future problems.

**However**, if your engine is **stock, lightly used, and runs smoothly**, a **basic rubber or polyurethane balancer** (such as a standard OEM replacement) may be sufficient and more budget-friendly. In such cases, the extra cost of the Powerbond unit may not justify the benefits.

**Final Recommendation:**

- **For stock engines with no vibration issues** A **standard replacement balancer** (OEM or aftermarket rubber/polyurethane) is likely adequate.

- **For modified, high-performance, or rough-running engines** The **Powerbond Dayco SX-1187 is strongly recommended** due to its superior durability and vibration control.

- **For classic trucks kept for long-term use** The investment in the Powerbond balancer is worthwhile to prevent future failures and maintain smooth operation.

Always ensure **proper installation** by following manufacturer guidelines or consulting a trusted mechanic. If the engine has **known internal issues**, address those first before upgrading the balancer.

Details:

Dayco Engine Harmonic Balancer for 1966-1972 Chevrolet Impala 6.5L 6.6L 7.0L ol: Status: In Stock.

part #: sx1187 price

  • $54.99

specifications cranshafengin:

  • for models: Impala
  • for makes: Chevrolet
  • for years: 1966-1972
  • brand: Powerbond By Dayco
  • mpn: Sx-1187
  • item weight: 10.0700
  • ipn: C674 25-35
  • placement on vehicle: Engine Cylinder Block
  • compatible year: 1972 1971 1970 1969 1968 1967 1966
  • 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: 2.686 In / 68.20 Mm
  • hardware included: No
  • ring width: 1.378 In / 34.98 Mm
  • counterweight balance: Neutral, No Counterweight
  • outer ring material: Steel
  • overall outside diameter: 6.979 In / 177.25 Mm
  • nose outside diameter: 2.333 In / 59.25 Mm
  • crank bore: 1.599 In / 40.60 Mm

offer cranshafengin:

  • started: March 1, 2026
  • quantity: 1
  • availability: In Stock
  • options: Ship-to-home
  • sold: 0

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seller cranshafengin:

  • rating: 99.5%
  • city: Indianapolis, Indiana
  • # reviews: 627635

general cranshafengin:

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

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  • type: Fixed
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  • time: 30 Days
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for models: impala, for makes: chevrolet, for years: 1966-1972, item weight: 10.0700, placement on vehicle: engine cylinder block, compatible year: 1972 1971 1970 1969 1968 1967 1966, 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: 2.686 in / 68.20 mm, hardware included: no, ring width: 1.378 in / 34.98 mm, counterweight balance: neutral, no counterweight, outer ring material: steel, overall outside diameter: 6.979 in / 177.25 mm, nose outside diameter: 2.333 in / 59.25 mm, crank bore: 1.599 in / 40.60 mm,
category: auto parts > car truck parts accessories > engines engine parts > crankshafts, sku: 19110151817797603,
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