Choosing the Right Spark Plug Wire Set for Your 1987 Chevrolet V20
Get your classic Chevy truck running smoothly with the correct new spark plug wires.
- Symptoms of bad wires include rough idle, misfiring, and poor acceleration.
- For a stock daily driver, brands like NGK and Denso offer the best value and reliability.
- If your truck has headers or other engine mods, consider performance wires from MSD or Taylor for better heat resistance and spark delivery.
- Always replace wires one at a time to avoid mixing up the engine's firing order.
Is It Time for New Wires?
Spark plug wires don't last forever. The insulation breaks down from high engine heat, oil, and simple age. When this happens, the electrical energy can leak out before it reaches the spark plug. This causes a weak spark or no spark at all.
Symptoms of Failing Spark Plug Wires:
- Rough Idle: Your truck may shake or vibrate more than usual when stopped.
- Engine Misfires: You might feel a stumble or hesitation from the engine, especially when accelerating. This happens when a cylinder fails to fire correctly.
- Poor Acceleration: The truck may feel sluggish and lack power.
- Reduced Fuel Economy: A weak spark means wasted fuel, so you'll find yourself at the gas pump more often.
- Check Engine Light: A persistent misfire can trigger the Check Engine Light.
- Visible Damage: Look for cracks, burns, or melting on the wire insulation or boots. You might even see a blue spark jump from the wire to a metal part of the engine in the dark, which is a sure sign of a leak.
Pro Tip: The Spray Bottle Test
In a dark garage, start your V20's engine and lightly mist the spark plug wires with water from a spray bottle. If you see small sparks arcing from the wires to the engine block, the insulation has failed and the wires need to be replaced immediately.
Choosing the Right Aftermarket Wires
For a classic truck like the 1987 V20, you have many aftermarket options. Original Equipment (OEM) wires were made by ACDelco. While you can still get ACDelco wires, many aftermarket brands offer excellent or even superior performance. They generally fall into three categories.
Tier 1: OEM-Quality Replacements
These brands are perfect for a daily driven or stock V20. They provide reliable performance and a perfect fit without a high price tag. They are a safe, dependable choice.
- NGK: Often considered a top-tier replacement, NGK wires are known for excellent quality and durability.
- Denso: Another excellent Japanese brand that is a direct competitor to NGK, offering similar quality and performance.
- Delphi: As a major OEM supplier, Delphi wires offer a factory-like fit and reliable function.
- Standard Motor Products (SMP): A long-standing aftermarket brand that is a trusted choice for standard replacement parts.
Tier 2: Performance & Heavy-Duty
If your V20 has engine modifications like headers, a high-output ignition, or if you simply want a more durable and performance-oriented wire, these brands are for you. They often feature thicker 8.5mm+ jackets and lower resistance for a hotter spark.
- MSD: A leader in performance ignitions. Their Super Conductor wires have very low resistance and are a popular choice for both performance and looks.
- Taylor Cable: Known for quality performance wires in various colors, allowing for some engine bay customization.
- Accel: This brand offers a range of wires. Their higher-end sets with ceramic boots are a great choice if you have headers, as they offer superior heat resistance. User reviews on their standard wires are mixed.
A Note on Wire Diameter and Resistance
Performance wires are often advertised by their diameter (e.g., 8.5mm, 10.5mm) and low resistance (measured in ohms per foot). A thicker wire provides better insulation, while lower resistance means more energy reaches the spark plug. For a stock engine, this difference may not be noticeable, but for a modified, high-compression engine, it can be beneficial.
Estimated Costs
| Part Type | Price Range |
|---|---|
| New Aftermarket | $30.22 - $196.37 |
| New OEM (ACDelco) | $45 - $90 |
| Shop Labor | $75 - $150 |
Frequently Asked Questions
Do I really need expensive performance wires?
For a stock 1987 V20, no. A quality set from NGK or Denso will work perfectly. Performance wires are most beneficial for modified engines or if you need extra heat protection from aftermarket exhaust manifolds (headers).
Why is it important to replace wires one at a time?
Your V20's engine has a specific firing order. Each wire is a different length and must go from the correct terminal on the distributor cap to the correct spark plug. Replacing them one by one ensures you don't mix up the order, which would cause the engine to run poorly or not at all.
What is dielectric grease and should I use it?
Dielectric grease is a non-conductive, silicone-based grease. Applying a small amount inside the spark plug wire boots helps seal out moisture and prevents the boots from getting stuck to the spark plugs or distributor cap. It makes future wire changes much easier.
Can I just replace the one bad wire?
It's best to replace the wires as a complete set. If one wire has failed due to age, the others are likely not far behind. Replacing them all at once ensures consistent performance and prevents you from having to do the job again in a few months.
Technical Specifications
OEM Part Numbers: 9748RR (ACDelco Professional)
The 1987 V20 uses a distributor-based ignition system. Wires connect from the HEI-style distributor cap to the spark plugs. Aftermarket wires are typically spiral core, offering a balance of low resistance and RFI suppression. Wire diameter varies from a stock-like 7mm or 8mm to performance-oriented 8.5mm and larger.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Chevrolet V20:
- 🛍️ Shop This Part
- Is It Time for New Wires?
- Symptoms of Failing Spark Plug Wires:
- Pro Tip: The Spray Bottle Test
- Choosing the Right Aftermarket Wires
- Tier 1: OEM-Quality Replacements
- Tier 2: Performance & Heavy-Duty
- A Note on Wire Diameter and Resistance
- Estimated Costs
- Frequently Asked Questions
- 🎟️ Get 5% Off