Choosing the right camshaft for your 5.3L engine with 706 heads can greatly improve performance and drivability. The 5.3L engine, part of the LS engine family, is known for its durability and potential for power gains when properly upgraded.
One of the best and most cost-effective upgrades you can make is swapping out the stock camshaft for one that is specifically designed for your 706 heads.
The 706 heads are a popular choice when looking to improve the performance of a 5.3L engine. These heads are known for their excellent flow characteristics and ability to handle both naturally aspirated and boosted applications.
When selecting the best camshaft for your engine, it’s essential to consider your specific goals, such as increasing horsepower, torque, or improving overall drivability. In this article, we will explore some of the top picks.
Understanding 5.3L Engines
The 5.3L LM7 is a popular LS engine with a displacement of 5.3 liters and an iron block. This engine provides a great balance of power and fuel efficiency.
Some relevant features of the 5.3L LM7 LS engine include:
- Iron block construction
- Varied applications, such as trucks and SUVs
- Stock heads can be upgraded with 706 heads for added performance
Upgrading stock heads to 706 heads can result in significant power improvements. For example, dyno testing on an LM7 5.3-liter engine showed that the 706 heads were worth 20 hp and 15 lb-ft over a pair of 317 heads1.
Selecting the best cam to pair with 5.3L engines using 706 heads takes into account various factors. A cam like the Z06 cam could add 40-50hp with proper exhaust2.
Cam selection also depends on the intended use of the vehicle, the levels of performance you seek, and any additional modifications you plan to make.
706 Heads and Their Features
The 706 heads are a popular choice for 5.3L LS series engines.
- Known for their affordability and power
- Exceptional flow characteristics
- Superior to 862 heads in reliability and performance
These heads have a cathedral-port design offering better flow compared to other stock LS heads. Ported 706 heads can further improve performance as porting increases airflow and efficiency.
- Size: 61.5 cc (smaller than 317 heads)
- Ideal for maintaining compression
Due to their smaller combustion chambers, the 706 heads prevent compression loss which is beneficial for engine performance. While they might not offer the best flow out of all the LS head options, they still provide excellent performance for budget builds.
Feature Comparison Table
|Head||Flow||Reliability||Combustion Chamber Size|
|317||Superior (larger valves)||Good||Larger|
|Ported 706||Excellent||High||61.5 cc|
Therefore, 706 heads are a great choice for those looking to get the most bang for their buck in a 5.3L LS build.
Their features make them ideal for a variety of applications, including improved engine performance and reliability.
Choosing the Best Cam for 5.3 with 706 Heads
When selecting the best camshaft for a 5.3 engine with 706 heads, there are a few factors to consider. These include lift, duration, Lobe Separation Angle (LSA), and compatibility with your engine’s setup.
Lift: Higher lift cams provide better airflow, which can increase power. Stock heads on a 5.3 can handle moderate increases in lift.
Duration: Higher duration cams keep the valves open longer, improving power at higher RPMs. Balancing duration with lift is key for optimal performance.
Some popular cam options for 5.3 engines with 706 heads include:
- Pro LS Cam
- LM7 Cam
|Camshaft||Lift (intake/exhaust)||Duration @ 0.050″ (intake/exhaust)||LSA|
|Pro LS Cam||0.600″/0.600″||233°/246°||113|
Before choosing a cam, consider the following points:
- Match the cam to the application and other engine components
- Ensure proper valve spring kit compatibility
- Check compatibility with the valvetrain and intake system
Finally, note that cam swaps can lead to significant power gains, particularly with the 706 heads, which are known for strong performance in stock-trim 5.3 engines.
Performance Upgrades and Modifications
Upgrading the cam on a 5.3 engine with 706 heads can greatly enhance performance and power. One key aspect to consider is the intake as:
- A high-flow intake manifold can boost the engine’s power.
- Hooker headers can further enhance the performance, improving exhaust flow.
When upgrading the cam, a valve spring upgrade may be necessary. This is because:
- Stronger valve springs support the increased lift and duration of an aftermarket camshaft.
- A proper tune is essential to optimize power and drivability.
Let’s compare two popular cam options for 5.3 engines with 706 heads:
|Camshaft Option||Power Gains||Pros||Cons|
|Mild Cam||Moderate||Easy installation, suitable for daily driving||Limited power gains|
|Aggressive Cam||Significant||Largest power gains, best for racing applications||May require additional supporting mods, less street friendly|
- A high-flow intake and Hooker headers can improve power.
- A valve spring upgrade may be needed when installing a new cam.
- Adequate tuning is essential for optimum performance.
Power and Torque Gains
When looking for the best cam for a 5.3L engine with 706 heads, it’s crucial to consider power and torque gains. An effective cam upgrade aims to maximize real-world performance for LS-powered trucks.
For instance, swapping a stock LM7 cam to a BTR torque cam results in significant power and torque improvements1.
Before the cam swap, the 5.3L produced 348 hp at 5,200 rpm and 374 ft.-lbs. of torque at 4,400 rpm3. After installing the BTR cam, the peak numbers jumped to 385 hp at 5,500 rpm and 393 ft.-lbs. of torque at 4,700 rpm3.
Another example is when a 5.3L engine received a COMP cam and valve spring upgrade4. The modified engine produced 442 hp at 6,200 rpm and 412 lb-ft of torque at 5,000 rpm4. However, there was a slight drop in torque below 2,900 rpm4.
|Cam Type||Peak Horsepower||Peak Torque|
|Stock LM7 Cam||348 hp||374 ft.-lbs.|
|BTR Torque Cam||385 hp||393 ft.-lbs.|
|COMP Cam||442 hp||412 lb-ft|
In general, power and torque gains are achievable through cam swaps and upgrades. However, be aware of potential trade-offs, such as a slight decrease in low-speed torque.
Camshaft Brands and Products
ATI: This is a well-established brand in the automotive industry. They offer high-quality components, including camshafts for 5.3 engines. Besides, it is highly recommended for their:
- Proven track record for durability and performance
- Excellent fit for 706 heads
Brian Tooley Racing (BTR): This is another top player in the market, offering a range of cams designed for LS engines like the 5.3 with 706 heads. Their stage 4 cam and the torque cam are popular choices.
This product is recommended due to the following factors:
- Highly compatible with 5.3 engines and 706 heads
- Improves overall engine performance
The LS9 and LS3 camshafts are also worth considering. Compatible with the 5.3 engine and 706 heads, they deliver substantial power gains. These camshafts can work perfectly due to the following factors:
- They enhance low-end torque and high-RPM horsepower
- They are ideal for both street and track performance
A comparison table for these camshaft options is provided below:
|Brand/Model||Compatibility||Power Gains||Performance Range||Side Effects|
|BTR Stage 4 Cam||High||High||Street/Track||Increased lope|
|BTR Torque Cam||High||Moderate||Street/Track||Minimal|
|LS9 Cam||Moderate||Moderate||Street/Track||Firm idle|
|LS3 Cam||Moderate||Moderate||Street Performance||Incompatibility with some stock components|
Therefore, options like ATI, BTR, LS9, and LS3 camshafts can help you extract the best performance from your 5.3 engine with 706 heads.
Consider the compatibility, power gains, and possible side effects when choosing the best camshaft for your vehicle.
Additional Components and Support
When upgrading the cam on a 5.3 with 706 heads, additional components need to be addressed. These include:
- Rocker arms
- Valve covers
- Front cover
- Cam gear
- Valve job
Upgraded springs are necessary for cam swaps. For example, BTR “Truck Norris” cam suggests using improved springs and rocker trunnions1. In addition, work on the ECM might be needed after a cam upgrade1.
- Lifters should be upgraded for better performance. With a cam swap, consider high-quality hydraulic roller lifters. Make sure to find the correct type for LS engines.
- When upgrading rocker arms, consider trunnion bearings. These can decrease friction and improve durability and performance.
- Increased stability under heavy load can be provided by aftermarket rocker arm solutions.
Job of the Valve
- Improved airflow and power
- Enhances valve sealing and longevity
- Can help maximize cam upgrade benefits
A new damper is important for reducing harmonics. This can minimize wear and increase overall engine life.
Setting TDC (top dead center) is critical during the cam upgrade process. Accurate timing is essential to avoid engine damage.
A comparison table for valve covers
|Feature||Stock Valve Covers||Aftermarket Valve Covers|
|Ease of Use||Good||Improved|
Consider using an upgraded front cover for better engine aesthetics and improved sealing. New cam gear may be needed depending on camshaft model and type.
Compatibility and Swapping
When considering cams for a 5.3 with 706 heads, compatibility is essential. 862 and 243 heads are alternatives that work well.
- 862 heads: These are also compatible with 5.3 engines, similar to 706 heads. However, they offer slightly less power potential.
- 243 heads: A popular choice for LS enthusiasts, they provide higher power gains when matched with the right cam.
Cam swapping with 5.3 engines typically benefits from using LS3-type springs. These springs improve valve control and stability, complementing the cam swap.
In addition to 5.3 engines, cam swaps and head combinations can also benefit other engines, like:
- 4.8L (LR4): Smaller bore engines, such as the 4.8L, can use 706 heads, although achieving less power than with the 5.3.
- 6.0L (LQ4 and LQ9): Upgrading these larger engines with 706, 862, or 243 heads requires a single-pattern cam to optimize power gains.
Cam specs play a vital role in compatibility as well.
For example, a single-pattern cam with 224 duration and 112 LSA works best with mildly ported 706 heads.
|Engine||706 Heads||862 Heads||243 Heads|
|6.0 (LQ4 and LQ9)||Moderate||Moderate||Best|
When looking for the best cam for a 5.3 with 706 heads, consider compatibility with heads and cam specs, and explore alternatives for optimal results.
Tuning and Management
When building a 5.3 engine with 706 heads, the tuning and management aspect is important to maximize performance. Using a Holley HP management system can help fine-tune the engine for optimal results.
Some key components to consider when tuning your 5.3 with 706 heads:
- Injectors: Choosing the right size and type of injectors is crucial for efficient fuel delivery. For example, upgrading to 42 lb/hr injectors can provide better fuel atomization and improved throttle response.
- ECU: Retuning the ECU is necessary to accurately adjust fuel and ignition maps. This ensures the best performance results and smoother engine operation.
- Fuel Pump: Upgrading your fuel pump to a higher flowing unit, like a Walbro 255 LPH, benefits fuel delivery and helps maintain steady fuel pressure.
A popular choice to optimize tuning and management is the Meziere electric water pump. This pump offers:
- Improved cooling capacity
- Reduced power draw from the engine
- Light-weight design
While selecting the right components and tuning the engine, it’s essential to strike a balance between performance and drivability.
Comparing a few popular performance parts for a 5.3 with 706 heads:
|Holley HP ECU||User-friendly interface||Can be expensive|
|42 lb/hr Injectors||Better fuel atomization||Requires proper ECU tuning|
|Meziere Electric Pump||Improved cooling||May necessitate radiator modifications|
Remember, it’s important to tailor tuning and management to your specific application and ensure all components work together harmoniously to maximize performance.
For Truck Owners and Enthusiasts
Finding a suitable cam for 5.3 with 706 heads can greatly improve your truck’s performance. Truck owners and LS truck enthusiasts alike should consider important factors, such as lift and piston-to-valve clearance.
A low-lift truck cam is perfect for improving low-end torque and drivability. This makes it ideal for demanding applications like towing or off-roading.
For example, a BTR “Truck Norris” cam is designed for street-driven 5.3 and 6.0 truck engines, and can significantly improve overall performance.
When choosing a truck cam, it’s crucial to ensure sufficient piston-to-valve clearance. This prevents engine damage during operation.
Proper piston-to-valve clearance is critical to ensure reliability and longevity of the engine.
Another key consideration is the lobe separation angle (LSA). A wider LSA provides smoother idle and better low-end performance, while a narrower LSA tends to result in snappier throttle response and increased high-RPM power.
For instance, the LM7 5.3L cam has an LSA of 116 degrees, while the LS3 cam has an LSA of 117 degrees.
When upgrading your truck cam, it’s essential to update supporting components. Hooker swap headers can help maximize your engine’s potential by improving exhaust flow and reducing backpressure.
To sum it up:
- Truck Cam: Choose a low-lift cam for improved torque and drivability.
- Piston-to-Valve Clearance: Ensure sufficient clearance to avoid engine damage.
- Lobe Separation Angle (LSA): A wider LSA provides smoother idle and better low-end performance, while a narrower LSA offers snappier throttle response and increased high-RPM power.
- Supporting Components: Upgrade necessary components like headers to maximize performance gains.
Naturally Aspirated vs Boosted Engines
When upgrading your 5.3 engine with 706 heads, choosing the right cam depends on whether you’re planning on running a naturally aspirated or boosted setup.
For a naturally aspirated setup, you’ll want a cam with a wider lobe separation angle (LSA) to achieve a good balance of power, torque, and drivability.
This type of cam works well for daily driving and moderate performance improvements. However, it may have limitations in terms of maximum power output.
- Improved performance without adding forced induction
- Less complexity and cost compared to a boosted setup
- Limited potential for maximum power
- Not as effective as a boost-ready cam for boosted setups
On the other hand, if you plan to add a turbocharger or supercharger, a boost-ready cam will optimize power and torque gains.
These cams generally have a narrower LSA and are specifically designed to work with increased cylinder pressures caused by forced induction.
- Optimized for use with a turbocharger or supercharger
- Higher power and torque potential
- Not ideal for naturally aspirated setups
- Increased complexity and cost of the overall setup
For both setups, it’s important to use components that can handle the increased cylinder pressures, such as quality fuel injectors and a high-performance fuel pump.
|Feature||Naturally Aspirated Cam||Boost-Ready Cam|
|Cost & Complexity||Lower||Higher|
|Ideal Use||Daily driving, moderate performance upgrades||Forced induction setups|
Selecting the optimal camshaft for your 5.3L engine with 706 heads is a critical step in unlocking enhanced performance. The combination of the LS engine’s inherent durability and the potential of the 706 heads can lead to substantial power gains.
Carefully choosing a camshaft that aligns with your performance goals, whether naturally aspirated or boosted, can make a remarkable difference.
With options from trusted brands like ATI, BTR, LS9, and LS3, you can harness the potential of your 5.3L engine while considering factors like compatibility, power gains, and side effects.
Upgrading components like injectors, ECUs, and fuel pumps is essential for fine-tuning your setup.
Whether you’re a truck enthusiast, seeking daily drivability or track performance, the right camshaft, when paired with complementary components, can elevate your 5.3 with 706 heads to new heights of power and efficiency.
Frequently Asked Questions
What is the optimal camshaft for a 5.3 Vortec with 706 heads?
The optimal camshaft for a 5.3 Vortec with 706 heads is subjective and dependent on your goals. However, the Brian Tooley Racing BTR Vortec Truck stage cam is a great choice for improved power and performance in daily driving situations.
Which cam swap can be done without removing heads on a 5.3 engine?
You can perform a “cam-in-block” swap, which allows for a camshaft swap without removing the cylinder heads on a 5.3 engine. Be sure to follow proper procedures and consult the service manual for detailed instructions.
What is the best LS cam upgrade for a 5.3 with 706 heads?
For a 5.3 with 706 heads, the Brian Tooley Racing BTR Vortec Truck stage cam is a popular choice for a significant power boost. This camshaft offers improved performance without compromising drivability.
How does the Summit Stage 4 LS cam compare to a Stage 2 cam?
The Summit Stage 4 LS cam offers higher peak power at the top end and might sacrifice low-end torque. In contrast, a Stage 2 cam typically provides a milder power increase, maintaining better low-end torque and drivability.
|Feature||Stage 2 Cam||Stage 4 Cam|
|Low-end Torque||Better||Potentially Less|
|Drivability||More Street-friendly||More Aggressive|
What are the benefits of an LS cam and lifter kit for a 5.3 with 706 heads?
- Improved power and torque
- Enhanced throttle response
- Better overall engine performance
How much horsepower can be added by using a Comp cam on a 5.3 LS with 706 heads?
The amount of horsepower added by a Comp cam on a 5.3 LS with 706 heads depends on the specific cam profile and supporting modifications. Generally, this upgrade can provide a moderate to significant power increase depending on your overall setup.