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Engine Valve Cover Gasket Set for the 1979 Chrysler 300

Stop oil leaks from the top of your 360 V8 and keep your classic Mopar running strong.

4 minutes to read 1978-1982 Chrysler 300
Difficulty
2/5
Est. Time
1.5 hrs
DIY Doable?
✅ Yes
Shop Labor
$120-$200
⚠️ Drivable, but... — Yes, but you should address it soon to prevent oil loss and a potential fire hazard from oil dripping on the hot exhaust.
Key Takeaways
  • The 1979 Chrysler 300 has a 5.9L (360) LA-series V8; ensure you buy gaskets for this specific engine family.
  • Modern aftermarket gaskets (rubber-coated fiber or molded rubber) from brands like Fel-Pro or Mahle are superior to original cork designs.
  • Proper cleaning of mating surfaces and correct, even torque on the valve cover bolts are critical to prevent new leaks.
  • While replacing the gaskets, inspect the PCV valve and grommet for wear and replace if necessary.
The engine valve cover gasket set on your 1979 Chrysler 300 has a simple but important job: it creates a seal between the valve covers and the cylinder heads of your 5.9L (360) V8 engine. This prevents motor oil, which is splashing around inside to lubricate the valvetrain, from leaking out onto your engine and exhaust. A good seal keeps the oil in, protecting your engine and keeping your engine bay clean.

Signs of a Failing Valve Cover Gasket

On a classic car like the 1979 Chrysler 300, gaskets are a common wear item. The original materials dry out, get brittle, and shrink over time. When the valve cover gaskets fail, you'll notice a few key symptoms.

Common Failure Symptoms

  • Burning Oil Smell: This is the most common sign. As oil leaks from the valve covers, it drips onto the hot exhaust manifolds, creating a distinct and unpleasant burning smell.
  • Visible Oil Leaks: You may see oil residue or wetness around the top of the engine, specifically where the valve covers meet the cylinder heads. Over time, this can attract a lot of dirt and grime.
  • Low Engine Oil: A significant leak can lead to a noticeable drop in your engine oil level between changes, potentially putting the engine at risk if not addressed.

Choosing the Right Aftermarket Gasket

For a vehicle like the '79 300, finding a New Old Stock (NOS) OEM gasket is nearly impossible and not necessary. Modern aftermarket gaskets offer superior materials and technology compared to what was available in the late 1970s. The single engine offered in the 1979 300 was the robust E58-coded 5.9L (360 c.i.) V8, the same high-performance engine used in police-spec Mopars of the era. This makes finding a quality aftermarket gasket straightforward.

Gasket Material Tiers

  • Good: Cork-Rubber Composite: Brands like Fel-Pro and Mr. Gasket offer high-density cork-rubber gaskets. These are a significant upgrade from original cork gaskets, as the rubber binder prevents leak paths and the material swells slightly when exposed to hot oil to improve its seal. They are a reliable and cost-effective choice for a stock or lightly modified engine.
  • Better: Rubber-Coated Fiber: Some Fel-Pro Performance gaskets use a stiff fiber material coated in latex rubber. This design is excellent for high-heat applications, which is relevant since the gaskets are near the exhaust manifolds.
  • Best: Molded Rubber: Modern molded rubber gaskets, often made from silicone or advanced synthetics, are the top choice for durability and sealing. Brands like Mahle offer gaskets engineered to handle thermal expansion and provide a long-lasting, reliable seal. They resist drying out and cracking much better than cork-based materials.

Pro Installation Tip

Proper installation is key to preventing leaks. Make sure both the valve cover and the cylinder head surfaces are perfectly clean and free of old gasket material and oil. When tightening the valve cover bolts, follow a crisscross pattern starting from the center and working your way out. Do not overtighten the bolts, as this can warp the valve cover or split the new gasket, causing a new leak. Using a torque wrench to achieve the factory-specified torque is highly recommended.

Vehicle Background and Known Issues

The 1979 Chrysler 300 was a unique, one-year-only model based on the Cordoba platform. It was a special package designed to evoke the performance heritage of the original 300 "letter series" cars. Every U.S. model came with the high-output 360 V8 engine, heavy-duty police-spec suspension, and unique styling. There are no specific recalls or Technical Service Bulletins (TSBs) from the National Highway Traffic Safety Administration (NHTSA) related to the valve cover gaskets for this model. Any issues today are primarily due to the age of the components. Owners on forums for classic Mopar vehicles frequently discuss replacing dried-out gaskets as part of routine maintenance to keep these cars on the road.

Estimated Cost Comparison
Part TypeEstimated Cost
New Aftermarket Gasket Set$25 - $50
Shop Labor$120 - $200

Frequently Asked Questions (FAQ)

Is this a difficult repair to do myself?

No, for most people with basic hand tools, this is a relatively easy and feasible DIY job. Access to the valve covers on the 360 V8 is generally good. The key is taking your time to clean the surfaces properly and tightening the bolts correctly. The difficulty rating is low, and it can typically be done in 1-2 hours.

Do I need to use sealant with the new gaskets?

It depends on the gasket type. Many modern rubber gaskets are designed to be installed dry. Cork-rubber gaskets sometimes benefit from a small dab of RTV sealant at the corners or curved sections. Always follow the specific instructions provided by the gasket manufacturer.

Are all gaskets for a Mopar 360 V8 the same?

For valve cover gaskets, yes. The 360 V8 used in your 1979 300 is part of the Chrysler LA small-block engine family (which includes the 273, 318, 340, and 360). Gaskets from reputable brands listed for a Mopar 360 LA engine will fit correctly. Note that this is different from the later 5.9L Magnum engine, which has different valve covers.

Should I replace anything else at the same time?

While you have the valve covers off, it's a good time to inspect the PCV (Positive Crankcase Ventilation) valve and its grommet. These are inexpensive parts that can become brittle and cause vacuum leaks or oil consumption issues. Replacing them is easy and recommended.

Technical Specifications

Engine: 5.9L (360 c.i.) Chrysler LA-series V8

Wrenchy
Article researched & written by
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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.

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