When it comes to the world of hot rodding and engine building, the Chevrolet small block is an iconic and enduring figure. For decades, these engines have powered countless classic cars, muscle cars, and race cars, and they continue to be a popular choice for enthusiasts today. One of the most important components of any engine is the cylinder head, and the Chevrolet small block has a number of different head options available. Among the most popular and well-respected are the 350 Chevy heads.
There are many reasons why 350 Chevy heads are so popular. First, they are relatively easy to find and affordable. Second, they are known for their good performance, both in terms of power and fuel economy. Third, they are relatively easy to modify, making them a good choice for enthusiasts who want to build a custom engine. However, there are also some potential drawbacks to using 350 Chevy heads. One is that they can be heavier than some other head options, which can affect the handling of a vehicle. Another is that they can be more difficult to seal, which can lead to leaks.
Overall, 350 Chevy heads are a good choice for a variety of applications. They offer good performance, are relatively easy to find and affordable, and are easy to modify. However, they can be heavier than some other head options and can be more difficult to seal. Ultimately, the best way to choose the right cylinder head for your engine is to consider your specific needs and goals.
The Best 350 Chevy Heads for Performance
Vortec 350 Heads
The Vortec 350 heads, introduced in 1996, represent a significant upgrade over earlier small-block Chevy heads. Featuring a revised combustion chamber design, improved port flow, and a higher compression ratio, they deliver impressive power gains without sacrificing much low-end torque. Vortex heads are commonly found on Vortec 5.7L engines from 1996 to 2002 and are a popular choice for those looking to enhance the performance of their 350 Chevy.
These heads feature:
- Revised combustion chamber design for improved air-fuel mixing
- Improved port flow for increased airflow
- Higher compression ratio for increased power
- Available in both “Vortec” and “L31” versions
- Compatible with both Vortec and LS-based engine blocks
| Vortec Head Specifications | Value |
|---|---|
| Combustion Chamber Volume | 64cc |
| Intake Port Volume | 170cc |
| Exhaust Port Volume | 76cc |
| Compression Ratio | 9.5:1 |
The Worst 350 Chevy Heads to Avoid
2. Vortec Heads (1996-2002)
Vortec heads were offered on Vortec 350 engines from 1996 to 2002. These heads feature small intake runners and a bathtub-shaped combustion chamber, both of which restrict airflow and reduce performance. Vortec heads also have a low compression ratio (9.4:1), which further limits power output.
The biggest problem with Vortec heads is the lack of aftermarket support. There are very few performance upgrades available for these heads, which makes it difficult to improve their performance.
Disadvantages of Vortec Heads:
| Disadvantage |
|---|
| Small intake runners |
| Bathtub-shaped combustion chamber |
| Low compression ratio |
| Lack of aftermarket support |
Due to these disadvantages, Vortec heads are best avoided when building a performance 350 Chevy engine.
Identifying the Right 350 Chevy Head for Your Needs
Choosing the right 350 Chevy head for your engine can significantly impact performance. Consider the following factors:
Combustion Chamber Design
The combustion chamber shape affects the air-fuel mixture and combustion efficiency. Common designs include:
- Open Chambers: Ideal for low-compression engines and provide better airflow but require higher compression ratios.
- Closed Chambers: Reduce detonation and provide higher compression ratios but may restrict airflow.
- Rectangular Ports: Improve airflow at high RPMs but may require intake manifold modifications.
- Oval Ports: Provide an optimal balance of airflow and velocity, suitable for a wide range of applications.
Valve Train Configuration
The valve train setup determines the number and arrangement of valves, as well as the camshaft’s operation. Options include:
- Small Block (Traditional): 2 valves per cylinder with a pushrod-actuated rocker arm system.
- Vortec Heads: Improved airflow and swirl for better combustion, featuring 3 valves per cylinder.
- LS Series: Modern design with 4 valves per cylinder and a high-flow intake system, typically installed on GM LS engines.
Intake and Exhaust Ports
The size and shape of the intake and exhaust ports affect airflow and power output:
| Port Type | Flow Characteristics |
|---|---|
| Large Ports | Increased airflow capacity for high-performance applications |
| Small Ports | Improved low-end torque and fuel economy |
| Cathedral Ports | Optimized for low-RPM torque and provide better scavenging |
| Bowtie Ports | Designed for high-RPM performance and reduced intake turbulence |
Comparing Different 350 Chevy Head Configurations
When it comes to choosing the right cylinder heads for your 350 Chevy engine, there are a number of factors to consider. These include the engine’s intended use, the desired power output, and the budget. To help you make an informed decision, here’s a comparison of some of the most popular 350 Chevy head configurations available.
Aluminum vs. Iron Heads
Aluminum heads are lighter than iron heads, which can improve engine performance and fuel economy. However, aluminum heads are also more expensive than iron heads. Iron heads are more durable than aluminum heads, but they are also heavier and can reduce engine performance.
Vortec Heads
Vortec heads are a popular choice for performance applications. They feature a unique intake port design that helps to improve airflow and increase power. Vortec heads are available in both aluminum and iron versions.
L98 Heads
L98 heads are a good choice for street performance applications. They feature a larger intake runner volume than Vortec heads, which helps to improve low-end torque. L98 heads are typically made of iron.
AFR Heads
AFR heads are a high-performance aftermarket head that is designed for racing applications. They feature a number of advanced design features that help to increase airflow and power. AFR heads are typically made of aluminum.
| Head Type | Material | Intake Runner Volume (cc) | Exhaust Runner Volume (cc) |
|---|---|---|---|
| Vortec | Aluminum | 170 | 64 |
| Vortec | Iron | 170 | 64 |
| L98 | Iron | 180 | 64 |
| AFR | Aluminum | 210 | 72 |
The Benefits of Upgrading to an Aftermarket 350 Chevy Head
When it comes to upgrading the performance of your 350 Chevy engine, one of the best ways to do so is by installing an aftermarket cylinder head. Aftermarket heads are designed to improve airflow, which can lead to increased horsepower and torque. They can also improve fuel economy and reduce emissions.
Improved Airflow
The most significant benefit of upgrading to an aftermarket 350 Chevy head is improved airflow. Aftermarket heads are typically designed with larger valves and ports than stock heads, which allows for more air to enter and exit the combustion chamber. This increased airflow can lead to a significant increase in horsepower and torque.
Increased Horsepower and Torque
As a result of the improved airflow, aftermarket 350 Chevy heads can provide a significant increase in horsepower and torque. Depending on the specific head design and the other modifications made to the engine, it is possible to see gains of up to 50 horsepower and 75 lb-ft of torque.
Improved Fuel Economy
While it may seem counterintuitive, installing an aftermarket 350 Chevy head can actually improve fuel economy. This is because the increased airflow allows the engine to burn fuel more efficiently. This can lead to a reduction in fuel consumption of up to 5%.
Reduced Emissions
Another benefit of upgrading to an aftermarket 350 Chevy head is reduced emissions. The improved airflow and combustion efficiency can lead to a reduction in harmful emissions, such as hydrocarbons, carbon monoxide, and nitrogen oxides.
Types of Aftermarket 350 Chevy Heads
There are many different types of aftermarket 350 Chevy heads available on the market. Each type of head has its own unique advantages and disadvantages. Some of the most popular types of heads include:
| Head Type | Benefits | Disadvantages |
|---|---|---|
| Aluminum Heads | Lightweight, improved airflow, increased horsepower | More expensive than iron heads |
| Iron Heads | Less expensive than aluminum heads, durable | Heavier than aluminum heads, reduced airflow |
| Vortec Heads | Improved airflow, increased horsepower, reduced emissions | More expensive than traditional heads |
Common Issues with 350 Chevy Heads
Cracked Exhaust Manifolds:
The exhaust manifolds on 350 Chevy heads are prone to cracking, especially around the No. 6 cylinder. This is due to the high heat and stress placed on the exhaust manifold flanges. Symptoms of a cracked exhaust manifold include a loud exhaust leak, loss of power, and decreased fuel economy.
Warped Cylinder Heads:
The cylinder heads on 350 Chevy engines can warp over time, especially if they are subjected to extreme heat or cooling. This can lead to a loss of compression, coolant leaks, and performance problems. Symptoms of warped cylinder heads include overheating, decreased power, and a rough idle.
Valve Seat Recession:
The valve seats in 350 Chevy heads can recess over time, especially if the engine is run with unleaded fuel without the use of an additive. This can lead to a loss of compression, decreased power, and a rough idle. Symptoms of valve seat recession include a noisy valvetrain, increased oil consumption, and decreased fuel economy.
Intake Manifold Gasket Leaks:
The intake manifold gasket on a 350 Chevy head can leak over time, especially if the engine is run at high temperatures or has a high mileage. This can lead to a loss of power, decreased fuel economy, and a rough idle. Symptoms of an intake manifold gasket leak include a vacuum leak, coolant leaks, and a rich-running engine.
Head Bolt Hole Stripping:
The head bolt holes on 350 Chevy heads can strip over time, especially if the head bolts are over-tightened or the engine is subjected to extreme stress. This can lead to a loss of compression, coolant leaks, and performance problems. Symptoms of stripped head bolt holes include a noisy engine, decreased power, and a rough idle.
Cracked Exhaust Manifolds Around the No. 6 Cylinder
The No. 6 cylinder on a 350 Chevy engine is known for being particularly prone to exhaust manifold cracking. This is due to the fact that the No. 6 cylinder is located at the rear of the engine, where it is exposed to the most heat from the exhaust manifold. The exhaust manifold on a 350 Chevy engine is also made of cast iron, which is a brittle material that is prone to cracking under stress.
The symptoms of a cracked exhaust manifold around the No. 6 cylinder include a loud exhaust leak, loss of power, and decreased fuel economy. If you suspect that your exhaust manifold is cracked, you can have it inspected by a mechanic. The mechanic will be able to determine if the exhaust manifold is cracked and will recommend the best course of action.
| Issue | Symptoms |
|---|---|
| Cracked exhaust manifolds | Loud exhaust leak, loss of power, decreased fuel economy |
| Warped cylinder heads | Overheating, decreased power, rough idle |
| Valve seat recession | Noisy valvetrain, increased oil consumption, decreased fuel economy |
| Intake manifold gasket leaks | Vacuum leak, coolant leaks, rich-running engine |
| Head bolt hole stripping | Noisy engine, decreased power, rough idle |
The History and Evolution of 350 Chevy Heads
7. Performance Heads: The Ultimate Upgrade
For those seeking the ultimate performance boost for their 350 Chevy engine, aftermarket performance heads are the way to go. These heads are designed with larger valves, optimized port shapes, and improved combustion chamber designs to increase airflow and maximize power output. Performance heads come in various configurations, each tailored to specific performance goals and engine modifications. Some popular options include:
| Head Type | Valve Size | Port Shape | Combustion Chamber |
|---|---|---|---|
| Aluminum Pro Topline | 2.02″/1.60″ | Straight | 64cc |
| Trick Flow Twisted Wedge | 2.05″/1.60″ | Twisted Oval | 62cc |
| Edelbrock Performer RPM | 2.02″/1.60″ | D-Port | 64cc |
| Dart Pro 1 | 2.08″/1.60″ | Oval | 58cc |
Performance heads offer significant power gains, but they come at a higher cost and require additional modifications to the engine, such as camshaft and intake manifold upgrades, to fully unleash their potential. Proper tuning is also crucial to ensure optimal performance and reliability.
Expert Tips for Selecting the Best 350 Chevy Head
8. Considering Chamber Volume
Chamber volume plays a crucial role in determining the engine’s compression ratio. A higher compression ratio increases power and efficiency but can lead to detonation issues if not properly controlled.
Combustion Chamber Design
Chamber design greatly affects combustion efficiency. Different heads feature varying swirl or tumble patterns that promote optimal fuel mixing and flame propagation. Matching the chamber design to the intended engine setup and fuel type optimizes combustion and performance.
Valve Size and Placement
Larger and optimized valve sizes allow for greater airflow and improve engine breathing. The placement of the valves within the chamber can influence airflow dynamics and combustion efficiency. Proper valve positioning ensures optimal airflow and minimizes shrouding, resulting in improved power output.
Material and Construction Quality
Head material and construction quality directly impact durability and performance. Cast iron heads offer excellent strength and durability, while aluminum heads provide weight savings and better heat dissipation. The quality of casting, machining, and assembly techniques ensures proper fitment, sealing, and overall performance.
Avoiding Common Pitfalls When Choosing a 350 Chevy Head
9. Consider the Intake and Exhaust Port Shape
The intake and exhaust port shape significantly impacts engine performance. Different port designs can affect flow characteristics, mixture distribution, and air velocity. Match the port shape of the head to your specific engine build and goals.
Factors to Consider:
| Port Shape Characteristics | Effects |
|---|---|
| Straight ports | High flow potential, improved low-end torque |
| Twisted ports | Improved air distribution, increased peak power |
| Raised ports | Increased valve lift potential, improved high-RPM performance |
| Rectangular ports | Good for large displacement engines, broad power band |
| Oval ports | Improved airflow, can support higher RPM |
- Flow capacity: The port area determines the maximum amount of air that can flow through the head. A larger port allows for more airflow and higher power potential.
- Port velocity: The port’s shape and length impact the air’s velocity. Higher velocity helps prevent fuel puddling and improves combustion efficiency.
- Mixture distribution: The port should promote an even distribution of air and fuel to each cylinder. This ensures optimal combustion and balanced performance.
- Air attachment: The port should encourage air to stay attached to the cylinder wall as it enters, which helps improve airflow and power output.
10. Vortec Heads
The Vortec heads, introduced in 1996, were a major upgrade over the previous TBI heads. They featured larger intake and exhaust valves, a revised combustion chamber design, and improved airflow. These heads were used on all GM small-block V8 engines from 1996 to 2002, and they remain popular with performance enthusiasts today.
Pros:
- Increased power and torque
- Improved fuel economy
- Reduced emissions
- Easy to find and affordable
Cons:
- Not the most optimal design for high-performance applications
- May require some modifications to install on older engines
Compatibility:
| Engine | Vortec Heads |
|---|---|
| 1996-2002 GM Small-Block V8 | Yes |
| Pre-1996 GM Small-Block V8 | Requires modifications |
Performance Gains:
| Application | Power Increase | Torque Increase |
|---|---|---|
| Stock Vortec engine | 15-25 hp | 15-25 lb-ft |
| Modified Vortec engine | 40-60 hp | 40-60 lb-ft |
350 Chevy Heads: The Best and the Worst
The small block Chevy engine is one of the most popular and versatile engines ever made. It has been used in everything from classic muscle cars to modern performance vehicles. One of the most important components of any engine is the cylinder head. The cylinder head is responsible for sealing the combustion chamber and controlling the flow of air and fuel into and out of the engine. There are many different types of cylinder heads available for the small block Chevy, and each one has its own advantages and disadvantages.
Some of the best 350 Chevy heads include:
- Vortec heads: These heads were developed by GM in the late 1980s and early 1990s. They feature a swirl-port design that helps to improve air flow and combustion efficiency. Vortec heads are available in both aluminum and iron versions.
- Bowtie heads: These heads were developed by GM in the early 2000s. They feature a rectangular port design that is similar to the ports found on LS engines. Bowtie heads are available in both aluminum and iron versions.
- Edelbrock heads: Edelbrock is a leading manufacturer of aftermarket cylinder heads. They offer a wide variety of heads for the small block Chevy, including heads designed for street performance, drag racing, and oval track racing.
Some of the worst 350 Chevy heads include:
- Pre-Vortec heads: These heads were used on small block Chevy engines from the 1950s to the late 1980s. They feature a dated design that does not flow air or fuel very well. Pre-Vortec heads are not recommended for performance applications.
- Iron heads with small valves: Iron heads are typically heavier than aluminum heads, and they do not conduct heat as well. Small valves can restrict air flow and horsepower. Iron heads with small valves are not recommended for performance applications.
- Cracked heads: Cracked heads can cause a variety of problems, including coolant leaks, oil leaks, and combustion problems. Cracked heads should be repaired or replaced as soon as possible.
People Also Ask About 350 Chevy Heads: Best and Worst
What are the best 350 Chevy heads for street performance?
The best 350 Chevy heads for street performance are the Vortec heads. They offer a good balance of airflow, combustion efficiency, and durability.
What are the best 350 Chevy heads for drag racing?
The best 350 Chevy heads for drag racing are the Bowtie heads. They offer excellent airflow and combustion efficiency, and they are available in a variety of port sizes to meet the needs of different drag racing applications.
What are the worst 350 Chevy heads?
The worst 350 Chevy heads are the pre-Vortec heads. They offer poor airflow and combustion efficiency, and they are not recommended for performance applications.
How can I identify 350 Chevy heads?
There are a few ways to identify 350 Chevy heads. One way is to look for the casting numbers. The casting numbers are located on the top of the heads, between the valve covers. Another way to identify 350 Chevy heads is to look at the ports. The ports on 350 Chevy heads are typically rectangular.
