Will GT40P Cylinder Heads Fit on a Ford 302? A Comprehensive Guide

Discovering the compatibility of GT40P cylinder heads and the Ford 302 engine can be quite a challenge. If you’re seeking to upgrade your engine for better performance, this article is for you.

We’ll discuss whether GT40P cylinder heads are a viable option for your Ford 302 engine, the benefits of using them, and some potential challenges you may face during the process.

In short, yes, GT40P cylinder heads can fit on a Ford 302, but there are some considerations to keep in mind.

The GT40P Cylinder Head: An Overview

The GT40P cylinder head is a popular performance upgrade for Ford engines. It was originally designed for the Ford Explorer and was later found in some Mustang models.

The GT40P is an iron cylinder head with improved airflow and combustion chamber design compared to the stock heads on Ford 302 engines.

Characteristics of the GT40P Cylinder Head

  • Better airflow: The GT40P has larger intake and exhaust runners, which allow more air to flow through the engine. This increased airflow can lead to higher horsepower and torque gains.
  • Enhanced combustion chamber design: The GT40P features a more efficient combustion chamber shape, which can improve engine efficiency and produce more power.
  • Compatibility with the Ford 302: The GT40P shares the same bolt pattern as the Ford 302 engine, making it a viable option for upgrading.

Installation Considerations: Things to Keep in Mind

While GT40P cylinder heads are compatible with the Ford 302 engine, there are a few key considerations to keep in mind before diving into the installation process.

Swapping the Rocker Arms

The GT40P uses a pedestal-style rocker arm system, which differs from the stud-mount system found on most Ford 302 engines. You’ll need to swap out the rocker arms to ensure proper fitment and valve train geometry.

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Upgrading the Exhaust System

The GT40P cylinder heads have a unique exhaust port shape, which may require an upgrade to your existing exhaust system. Be prepared to invest in a set of GT40P-specific headers or modify your existing headers for proper fitment.

Tuning the Engine

After installing GT40P cylinder heads, you may need to retune your engine for optimal performance. This could involve adjusting the fuel and ignition maps in your engine management system or modifying the carburetor settings if you have a carbureted engine.

The Benefits of Upgrading to GT40P Cylinder Heads

So, why should you consider upgrading to GT40P cylinder heads on your Ford 302 engine? Here are a few compelling reasons:

  • Increased performance: The improved airflow and combustion chamber design can lead to noticeable power gains.
  • Better fuel efficiency: An efficient combustion chamber can lead to better fuel economy, making your engine more cost-effective in the long run.
  • Affordability: GT40P cylinder heads are often more affordable than aftermarket aluminum heads, making them an attractive option for budget-conscious enthusiasts.


GT40P cylinder heads can fit on a Ford 302 engine, but there are some important considerations to keep in mind before attempting the swap. Be prepared to swap out the rocker arms, upgrade the exhaust system, and potentially retune the engine.

With proper planning and execution, the GT40P cylinder head swap can be a rewarding upgrade that improves the performance of your Ford 302 engine.


  1. Can I use my existing intake manifold with GT40P cylinder heads? Yes, you can use your existing intake manifold with GT40P cylinder heads. However, you may need to use an intake manifold gasket that is compatible with both the GT40P heads and your intake manifold.
  2. Are there any clearance issues when installing GT40P cylinder heads on a Ford 302? There may be some clearance issues depending on your specific engine configuration, such as the valve cover clearance and the spark plug angle. It’s important to measure and check clearances before installation to avoid potential issues.
  3. Can I use my stock pushrods with GT40P cylinder heads? It is recommended to measure and verify the correct pushrod length for your specific engine combination. The use of aftermarket rocker arms may require a different length pushrod to maintain proper valve train geometry.
  4. How much horsepower gain can I expect from installing GT40P cylinder heads on my Ford 302? The horsepower gain will depend on various factors, such as your specific engine configuration, camshaft choice, and other supporting modifications. However, it is not uncommon for enthusiasts to see gains of 20-40 horsepower or more with a properly matched combination.
  5. Are there any other modifications I should consider when upgrading to GT40P cylinder heads? Upgrading your camshaft, valvetrain components, and intake manifold can further enhance the performance of your Ford 302 engine when paired with GT40P cylinder heads. Additionally, consider upgrading your ignition system and fuel delivery components to support the increased power output.
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