Ford 5.0 Smog Pump Delete Belt Size- What Is The Right Belt Size? 

When it comes to optimizing the performance of your Ford 5.0 engine, removing the smog pump can be a popular modification. 

The correct belt size for a Ford 5.0 smog pump delete is 6 ribs and 72 inches in length. This belt will fit all 1979-1993 Ford Mustangs with a 5.0L engine and no air conditioning. If your car has air conditioning, you will need a longer belt.

In this blog post, we will explore the importance of selecting the right belt size for a Ford 5.0 smog pump delete and provide you with the necessary information to make an informed decision.

Comparing Belt Sizes for Different Ford 5.0 Smog Pump Delete Configurations

The actual belt size that you need may vary depending on the specific make and model of your car. 

Here is a comparison of the belt sizes for different Ford 5.0 smog pump delete configurations-

ConfigurationEngine SizeAir ConditioningBelt Size
No AC5.0LNo6PK720
Power Steering5.0LNo6PK740
Power Steering5.0LYes6PK800
Power Steering5.0LYes6PK820

Factors to Consider for Ford 5.0 Smog Pump Delete Belt Sizing

When considering a smog pump delete and belt sizing for a Ford 5.0 engine, there are several factors you should take into account. Here are some important considerations-

Engine size 

The size of the engine will determine the length of the belt needed.

Air conditioning 

If the car has air conditioning, a longer belt will be needed.

Other accessories 

Some cars have other accessories, such as power steering or power windows, that will also need to be driven by the belt. These accessories will also affect the length of the belt needed.

Belt Length 

The belt size will depend on the specific configuration after the smog pump is deleted. Measure the distance between the pulleys to determine the appropriate length. 

Take into account any additional idler pulleys or accessories that may affect the belt routing.

Pulley Sizes 

Check the size of the pulleys involved in the smog pump delete. Smaller or larger pulleys may require different belt lengths to maintain proper tension and alignment. 

Consult the instructions provided with the smog pump delete kit for any specific recommendations.

Tensioner Adjustment 

If your Ford 5.0 engine has a tensioner, ensure it is properly adjusted to maintain the correct belt tension. 

The tensioner should have sufficient range to accommodate the new belt length without overstretching or causing excessive slack.

Belt Quality 

Choose a high-quality belt from a reputable manufacturer to ensure durability and reliability. 

Consider the specific demands of your application, such as high-performance modifications or extreme conditions, and select a belt that is suitable for those requirements.


Belts can range in price from a few dollars to over $100. It is important to find a belt that fits your budget, but don’t skimp on quality. A cheap belt may not last as long and could damage your engine.

Common Challenges in Determining the Right Belt Size

Determining the correct belt size for a Ford 5.0 smog pump delete can pose some common challenges. Here are a few factors that can make the process more difficult-

Lack of standardized information 

Since smog pump delete modifications involve removing the original emissions equipment, there is no standardized information available regarding the specific belt size required.

This makes it challenging to find accurate and reliable information.

Variations in setups 

There can be variations in how the smog pump delete is performed, with different aftermarket kits or custom setups available. 

These variations can affect the routing and tension requirements of the belt, making it harder to determine the correct size.

Limited documentation 

The documentation and instructions provided with smog pump delete kits may not always include detailed information about the recommended belt size. 

This can leave enthusiasts to rely on trial and error or seek information from online forums and communities.

Compatibility with other modifications 

The smog pump delete is often done in conjunction with other modifications to improve performance. 

These additional modifications, such as underdrive pulleys or different accessory configurations, can impact the belt routing and length requirements.

Belt tension adjustment 

Achieving the proper belt tension is crucial for proper operation and longevity. 

However, without a specific recommended belt size, it can be challenging to determine the correct tension to avoid slipping or excessive stress on other components.

Expert Tips for Selecting the Correct Ford 5.0 Smog Pump Delete Belt Size

When selecting the correct belt size for a Ford 5.0 smog pump delete, there are a few factors to consider. Here are some expert tips to help you choose the right belt size-

Measure the Pulley Sizes 

Start by measuring the diameter of the crankshaft pulley and the alternator pulley. These measurements are crucial in determining the correct belt length.

Determine the Pulley Configuration 

Take note of the pulley configuration after the smog pump delete. In some cases, an idler pulley or a shorter belt may be required to properly route the belt around the remaining pulleys.

Check for Belt Routing Diagrams 

Look for belt routing diagrams specific to your Ford 5.0 engine model. These diagrams can often be found in the vehicle’s service manual or online. 

They provide a visual representation of how the belt should be routed around the pulleys.

Consider a Serpentine Belt Conversion Kit 

If you are performing a smog pump delete along with a serpentine belt conversion, there are kits available that include the necessary pulleys and brackets. 

These kits often come with a recommended belt size, making the selection process easier.

Use a Belt Length Calculator 

Several online tools and mobile apps offer belt length calculators. Input the required measurements, pulley diameters, and configuration details to get an accurate belt length recommendation.

Test Fit and Verify Tension 

Once you have chosen a belt size based on the above considerations, test fit the belt and verify the tension. 

Ensure that the belt is properly tensioned, neither too loose nor too tight, as either condition can lead to premature belt wear or failure.

Frequently Asked Question

Here are the most common questions or FAQs about the right belt size for a Ford 5.0 smog pump delete, along with short and quick answers

How do I determine the right belt size for a Ford 5.0 smog pump delete?

To determine the correct belt size, measure the diameter of the crankshaft and alternator pulleys, consider the pulley configuration, consult belt routing diagrams, and use online belt length calculators.

Can I use the same belt size after removing the smog pump?

In most cases, the same belt size may not fit properly after removing the smog pump. The pulley configuration changes, so it’s important to measure and choose the right belt size accordingly.

Where can I find belt routing diagrams for my Ford 5.0 engine?

You can find belt routing diagrams specific to your Ford 5.0 engine in the vehicle’s service manual or search online. These diagrams provide guidance on how the belt should be routed around the pulleys.

Should I consider a serpentine belt conversion kit for a smog pump delete?

If you are performing a smog pump delete along with a serpentine belt conversion, using a conversion kit is recommended. These kits often include the necessary pulleys and brackets, along with a recommended belt size.

Can I rely on online belt length calculators?

Online belt length calculators can be helpful, but it’s important to input accurate measurements and pulley details. It’s a good idea to double-check the recommended belt size by consulting with experts or reliable sources.

How do I verify the tension of the belt after installation?

After installing the belt, ensure it is properly tensioned. It should neither be too loose nor too tight. Check the tension according to the manufacturer’s specifications to prevent premature belt wear or failure.

Where can I get expert advice or guidance on choosing the right belt size?

For expert advice, consider reaching out to experienced mechanics or joining online forums dedicated to Ford 5.0 engines. These resources can provide valuable insights and recommendations based on real-world experiences.


When performing a smog pump delete on a Ford 5.0 engine, it’s important to choose the right belt size to ensure proper functioning and avoid any complications. 

Consulting with a trusted mechanic or referring to the manufacturer’s guidelines is crucial in finding the correct belt size for a seamless modification.

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