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Choosing the Right Spark Plugs for Your 1987 GMC V2500

Get your classic GMC truck running smoothly with the correct new aftermarket spark plugs.

4 minutes to read 1987-1987 GMC V2500
Difficulty
3/5
Est. Time
1.5 hrs
DIY Doable?
✅ Yes
Shop Labor
$100-$200
⚠️ Drivable, but... — You can drive with failing spark plugs, but you will experience poor performance and fuel economy, and could risk further damage to ignition components or the catalytic converter over time.
Key Takeaways
  • For stock 1987 V2500 TBI engines, standard copper spark plugs from ACDelco or NGK are highly recommended for reliability and smooth operation.
  • The correct spark plug gap is critical for performance; it must be set to 0.035 inches.
  • Symptoms of failure include rough idle, poor acceleration, reduced fuel economy, and engine misfires.
  • No recalls or TSBs exist for spark plugs on this vehicle; they are a regular maintenance item.
Spark plugs are essential for your 1987 GMC V2500's engine. They take high-voltage electricity from the ignition system and create a spark. This spark ignites the mix of air and fuel inside the engine's cylinders. For the gasoline V8 engines in your truck, this combustion process is what creates power to move the vehicle. Without a strong, consistent spark, your engine can't run efficiently, leading to a variety of performance problems.

Signs of Failing Spark Plugs in Your V2500

When spark plugs wear out, they can't create a good spark. This can cause several noticeable problems with your truck. Being able to spot these signs can help you decide when it's time for a replacement.

  • Rough Idle: If your truck shakes or sputters when it's stopped and running, it could be due to a fouled or worn spark plug causing an engine misfire.
  • Poor Acceleration: A worn plug struggles to ignite the fuel mixture efficiently, making your truck feel sluggish or slow to respond when you press the gas pedal.
  • Worse Fuel Economy: Inefficient combustion means you're not getting the most out of your fuel. New plugs can sometimes improve gas mileage by a noticeable amount.
  • Engine Misfires: You might feel a hesitation or stumble from the engine while driving. This happens when a cylinder fails to fire correctly, often due to a bad spark plug.
  • Difficulty Starting: Weak or worn-out plugs can make it harder for the engine to start, especially in cold weather. You might notice the engine cranks for longer than usual before it starts.

Choosing the Right Aftermarket Spark Plugs

For your 1987 V2500, which came with a Throttle Body Injection (TBI) fuel system, you have a few choices. The type of plug you choose can make a difference in how your truck runs.

Plug Material: Copper vs. Iridium/Platinum

Your truck's engine was originally designed for copper spark plugs. Many experienced owners and mechanics recommend sticking with standard copper plugs, especially the OEM brand, ACDelco. They are inexpensive and provide excellent performance for these TBI engines. Their main downside is a shorter lifespan, typically needing replacement every 30,000 miles or so.

Iridium and platinum plugs are newer technology. They have a much longer service life. However, some owners report that these older TBI ignition systems can be sensitive and sometimes run rougher with platinum-style plugs. If your engine is stock, a quality copper plug is often the most reliable and cost-effective choice. Iridium plugs are a good option for modified or high-performance engines.

Brand Quality Tiers for the 1987 V2500

Tier Brands Notes
OEM Standard & Recommended ACDelco, NGK ACDelco is the original part for your GM truck. Many owners report the best and most consistent performance with standard ACDelco copper plugs. NGK is a highly respected brand that also works very well in these engines and is considered an OEM-quality equivalent.
Quality Aftermarket Autolite, Denso, Champion These brands offer reliable, budget-friendly copper plugs that meet or exceed OEM specifications. They are a solid choice for regular maintenance.
Performance / Specialty MSD, Accel These brands focus on high-performance applications. Accel makes "shorty" plugs that provide extra clearance if you have aftermarket headers that are close to the engine block. These are generally for modified trucks, not stock daily drivers.

A Note on Bosch Plugs

While Bosch makes quality parts, some forum discussions among owners of TBI-era GM trucks suggest that certain Bosch platinum plugs can cause rough running or misfire issues. If you choose Bosch, consider their copper or iridium options instead of platinum.

Known Issues, Recalls, or TSBs

There are no specific recalls or Technical Service Bulletins (TSBs) from the National Highway Traffic Safety Administration (NHTSA) related to spark plugs for the 1987 GMC V2500. Spark plugs are considered a standard maintenance item, and issues with them are typically resolved by routine replacement.

Check the Gap!

The most critical step when installing new spark plugs is ensuring they have the correct gap. For the V8 engines in the 1987 V2500, the specified gap is 0.035 inches. Even if plugs are advertised as "pre-gapped," you should always double-check them with a gap tool before installation. An incorrect gap can lead to poor performance and misfires.

Frequently Asked Questions (FAQ)

Do I need expensive iridium plugs for my truck?

For a stock 1987 V2500, you do not need expensive iridium plugs. In fact, many owners find their trucks run best on the standard, inexpensive copper plugs that the engine was designed for, such as the ACDelco CR43TS. Iridium plugs are best suited for high-performance or heavily modified engines.

What is the correct spark plug gap for my 1987 V2500?

The correct spark plug gap for the gasoline V8 engines (5.7L and 7.4L) is 0.035 inches. Always verify this with a gap tool before installing new plugs.

Should I replace my spark plug wires at the same time?

It is a good practice to inspect your spark plug wires when changing the plugs. If the wires are original or show any signs of cracking, brittleness, or corrosion, they should be replaced. Old wires can't deliver full voltage to the new plugs, reducing their effectiveness.

Why is my truck running rough after installing new platinum plugs?

The ignition systems on these older TBI trucks can be sensitive. They were designed for copper-core plugs. Some platinum plugs can interfere with the ignition signal, leading to a rough idle or misfires. If you experience this, switching back to a quality copper plug from a brand like ACDelco or NGK will likely solve the problem.

Technical Specifications

OEM Part Numbers: CR43TS

Spark Plug Gap: 0.035 in (0.9mm) Engine VIN (5.7L): K Thread Size: 14mm Seat Type: Tapered

Wrenchy
Article researched & written by
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Meet Wrenchy → Updated Apr 19, 2026

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.

Year Coverage
This article covers the Spark Plug for:
  • GMC V2500: 1987
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