Choosing the Right Distributor for Your 1975-1989 Chevrolet P20
Keep your classic P20's engine firing on all cylinders with a reliable new distributor.
- Most 1975-1989 P20s use a GM HEI distributor, but confirm if you have the large HEI or an older points-style unit before ordering.
- Mark the position of the distributor housing and rotor before removal to make installation much easier.
- You MUST set the ignition timing with a timing light after installing a new distributor.
- A failing distributor can cause a no-start or stalling, potentially leaving you stranded.
Is Your P20's Distributor Failing?
The distributor in your Chevrolet P20 works hard, spinning at half the engine's speed. Over tens of thousands of miles, its internal components can wear out. The electronic module inside an HEI distributor can fail, especially when it gets hot, leading to sudden stalling. The internal coil can also degrade over time, producing a weaker spark. If you're experiencing the symptoms below, your distributor is a likely culprit.
Symptoms of a Bad Distributor
- Engine Misfires: The engine may shake or stumble while driving, especially when you press the gas.
- Rough Idle: Your P20 may idle unevenly or sputter when stopped.
- Hard Starting or No Start: The engine cranks but struggles to fire up, or won't start at all. This can be intermittent.
- Stalling: The engine may die unexpectedly, sometimes after it has warmed up, and may start again after cooling down.
- Backfiring: A pop or bang from the engine or exhaust can indicate incorrect spark timing from a failing distributor.
Choosing the Right Aftermarket Distributor
For a vehicle like the P20, reliability is key. Original GM distributors are long discontinued, but the aftermarket offers a wide range of options from basic replacements to high-performance upgrades. Most P20s in this range use a V8 engine like the Chevy 350, for which parts are widely available.
Performance Upgrade Brands: FAST, Pertronix
If you're looking to improve performance and reliability, these brands are excellent choices. They are engineered for better spark and durability.
- FAST (Fuel Air Spark Technology): Known for high-end ignition systems, FAST distributors are made from high-quality materials like billet aluminum and are designed for precise timing and a powerful spark. They are a top-tier choice for those wanting maximum performance and longevity.
- Pertronix: A very popular name in the ignition world, Pertronix offers complete HEI distributors that are a significant upgrade over stock. They are engineered to work as a matched system, providing a stronger spark and better high-RPM performance than original units. They are a trusted choice for classic vehicle owners.
Standard Replacement Brands: Cardone (New), WAI Global
These brands aim to provide OE-quality performance for daily use. They offer a balance of quality and value.
- WAI Global: WAI manufactures 100% new distributors, not remanufactured ones, using materials that meet or exceed OE specifications. While the company promotes its quality, some user reviews are mixed, with occasional reports of parts failing early.
- Cardone: As one of the largest aftermarket suppliers, Cardone offers both new and remanufactured distributors. Their new units are a common choice for standard replacement, though some users in forums have reported quality issues.
Economy Brands: Replacement, Cardone (Remanufactured)
If budget is your primary concern, these options will get your P20 back on the road.
- Replacement: This is a generic category for house brands or value-focused parts. They are the most affordable option but may not offer the same longevity or performance as premium brands.
- Cardone (Remanufactured): A remanufactured distributor is an original unit that has been rebuilt with new wear components. They are a budget-friendly choice, but quality can vary.
Aftermarket Distributor Cost for 1975-1989 Chevrolet P20
| Tier | Brands | Price Range |
|---|---|---|
| Performance Upgrade | FAST, Pertronix | $250 - $465 |
| Standard Replacement | WAI Global, Cardone (New) | $150 - $250 |
| Economy | Replacement, Cardone (Reman) | $110 - $150 |
Pro Tip: Check Your Ignition System
Before replacing the entire distributor, inspect the cap and rotor for cracks, corrosion, or carbon tracking. Also, ensure your spark plug wires are in good condition and that your spark plugs are gapped correctly. One P20 owner traced a severe running issue to an incorrect spark plug gap, not a bad distributor.
Frequently Asked Questions (FAQ)
Can I upgrade my old points distributor to a new HEI distributor?
Yes, absolutely. Upgrading from a points-style distributor to an HEI unit is one of the most common and beneficial upgrades for older GM vehicles. It provides a stronger, more reliable spark, easier starting, and eliminates the need for regular points adjustments. The conversion is straightforward and requires running a new 12-volt power wire to the distributor.
Do I have to set the ignition timing after replacing the distributor?
Yes, this is a required step. The distributor controls when the spark plugs fire. After installing a new distributor, you must use a timing light to set the engine's initial timing to the manufacturer's specification. Failure to do so will result in poor performance, bad fuel economy, and potential engine damage.
What is the vacuum advance on the distributor for?
The metal can on the side of the distributor is the vacuum advance. It connects to the engine via a rubber hose. Its job is to advance the ignition timing based on engine load, which improves fuel economy and throttle response during cruising. When replacing a distributor, make sure this hose is connected correctly.
Is replacing the distributor a difficult job?
For a mechanically inclined owner, it is a manageable DIY job. The key is to carefully mark the position of the old distributor's housing and the direction the rotor is pointing before you remove it. This ensures the new distributor goes in with the correct orientation. The most common mistake is not getting the distributor gear to properly engage with the oil pump driveshaft at the bottom.
Technical Specifications
Most models will use a GM HEI (High Energy Ignition) style distributor with an integrated coil-in-cap design and a vacuum advance canister. It is driven by a gear on the camshaft.
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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.
- 🛍️ Shop This Part
- Is Your P20's Distributor Failing?
- Symptoms of a Bad Distributor
- Choosing the Right Aftermarket Distributor
- Performance Upgrade Brands: FAST, Pertronix
- Standard Replacement Brands: Cardone (New), WAI Global
- Economy Brands: Replacement, Cardone (Remanufactured)
- Aftermarket Distributor Cost for 1975-1989 Chevrolet P20
- Pro Tip: Check Your Ignition System
- Frequently Asked Questions (FAQ)
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