A Guide to Spark Plug Wire Sets for the 1955-1959 GMC PM153
Keep your classic GMC's engine running strong by choosing the right spark plug wires for your needs.
- Modern aftermarket spark plug wires from brands like Standard or Taylor are a quality upgrade over the original 1950s technology.
- Symptoms of failure include rough idle, engine misfires, and reduced fuel economy.
- Replacing wires is a simple, low-cost DIY job that can be done in under an hour.
- Always replace wires one at a time to avoid mixing up the engine's firing order.
Signs of Failing Spark Plug Wires
On a classic truck like the 1955-1959 GMC PM153, the ignition system is relatively simple, but worn-out parts can cause a lot of headaches. Spark plug wires live in a harsh environment and will eventually fail. Look for these common symptoms.
Common Failure Symptoms
- Rough Idling: The engine may shake or run unevenly when stopped.
- Engine Misfires: You might feel a hesitation or stumble from the engine, especially when accelerating.
- Reduced Power and Fuel Economy: When spark isn't delivered efficiently, your truck won't perform its best and will use more gas.
- Visible Arcing: In the dark, you might see small blue sparks jumping from the wires to a metal part of the engine. This is a sure sign of failed insulation.
- Cracked or Brittle Insulation: A visual inspection may reveal cracks, melting, or obvious damage to the wires' outer jackets.
Choosing the Right Aftermarket Wires
For a vehicle from this era, finding original equipment (OEM) parts is nearly impossible. The good news is that modern aftermarket spark plug wires are often a significant upgrade over the 1950s technology. Today's wires offer better insulation, conductivity, and durability. Your choice will depend on your goals for the truck.
Tier 1: Stock-Style Replacement
If you want to maintain a factory appearance and get reliable performance for a daily driver or a stock restoration, a standard replacement set is a great choice. Brands like Standard Motor Products offer quality wires that meet or exceed original specifications. They are designed to be a direct fit for your GMC's engine, whether it's a 6-cylinder or a V8.
Tier 2: Performance & Durability Upgrade
For owners who want enhanced performance, better heat resistance, and a more robust wire, a performance set is the way to go. Taylor Cable is a well-known brand in the classic and performance community, offering wires with features like silicone jackets and spiral-wound cores. These wires provide better radio frequency interference (RFI) suppression and can deliver a more consistent spark, which is beneficial for modified engines or for owners who simply want the best durability.
Pro Tip: When replacing your wires, change them one at a time. This ensures you don't mix up the firing order, which is essential for correct engine operation. Simply remove one old wire from the distributor cap and spark plug, and replace it with the new wire of the corresponding length.
Cost of a New Spark Plug Wire Set
The cost for a new set of spark plug wires is relatively low, making this a great value maintenance item. Prices will vary based on the brand and whether you choose a standard or performance set.
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket (Standard) | $27.18 - $60.00 |
| New Aftermarket (Performance) | $60.00 - $118.78 |
| Shop Labor | $75 - $150 |
Frequently Asked Questions
How often should I replace my spark plug wires?
For classic vehicles, there isn't a strict mileage interval. It's best to inspect them annually for any signs of wear, such as cracks, brittleness, or oil contamination. A good rule of thumb is to consider replacing them every 5 to 10 years, or whenever you perform a major tune-up with new spark plugs and a distributor cap.
What's the difference between carbon core and spiral core wires?
Original wires from the 1950s were often solid core, which created a lot of radio noise. Modern replacements use either a carbon core for radio suppression or a more advanced spiral-wound core. Spiral core wires, often found in performance sets like those from Taylor Cable, offer very low resistance for a strong spark while still preventing radio interference.
Do I need special tools to change my spark plug wires?
No special tools are usually required. A good pair of spark plug wire pullers can be helpful to avoid damaging the boots, but often you can remove them by hand with a firm twisting and pulling motion. Applying a small amount of dielectric grease inside the new boots will make future removal much easier.
Will performance wires give my truck more horsepower?
While performance wires won't magically add horsepower to a stock engine, they ensure that the maximum spark energy reaches the plugs. This can lead to a smoother, more efficient engine, especially under load. If your old wires were worn out, you will definitely feel a positive difference in performance with a new set, whether standard or performance.
Technical Specifications
The GMC PM153 from 1955-1959 was available with different engines, primarily GMC inline-six engines like the 248, 270, or 302 cu in, or a Pontiac-sourced V8. The correct wire set will depend on your specific engine. Sets include pre-cut wires for each cylinder plus a coil wire. Key differences between sets are the wire core (carbon vs. spiral wound) and the jacket material (EPDM vs. higher-temp silicone).
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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.