LS2 vs LS3 Engine Head

LS2 vs LS3 Engine Head
LS2 vs LS3 Engine Head

The LS series has a great bunch of engine heads that are more or less similar to each other. Such two engines are LS2 and LS3. They have a lot of common factors in terms of features and performances. Still, they are not the exact replacement for one another.  Let’s get into the detailed discussion and try to figure out the exact distinction between LS2 & LS3.

Reason to Compare

Among the LS based engines, people often get confused to choose the right one they need. This is because no clear comparison is available among them. With a view to helping the customers, we have come up with a practical review of both. You can only choose the better if you compare. So, let’s dive in and have a side by side analysis of both of their features and specs. For making you understand better, the following chart is prepared to highlight their areas of disparities.

LS2 vs LS3 Table

Compression Ratio10.9 : 1

Compression Ratio 10.7:1

Horsepower Rating 390-395 hp

Horsepower Rating 426-436 hp

Torque Rating 400 ft./lbs.

Torque Rating 420-428 ft./lbs.

Minimum Required Bore 4.000 inch

Minimum Required Bore 4.065 inch

Combustion Chamber Volume 65cc

Combustion Chamber Volume 68.7cc

Intake Valve Diameter 2.165"

Intake Valve Diameter 2.165"

Intake Port Style Cathedral

Intake Port Style Rectangular

Intake Runner Volume 210cc

Intake Runner Volume 257cc


Expensive Compare to LS3

LS2 Short Review

The LS2 is a revolutionary output of the LS platform. It was launched in the year 2005. At the very beginning, these engines had 24x reluctor wheels along with 1x cam sprockets. With time it gradually improved to a 58x reluctor and 4x cam sprocket. The enhancement on both the displacement and bore ensured more power and adaptability. That is why now it is adjustable with both LS1 and LS6 heads and with all the latest versions of LS3/L92.

The LS2 is technically addressed as the first Gen lV Chevrolet engine. It features 6.0L displacement. All the LS2 heads feature cathedral style intake ports. These ports are easily identifiable due to the tall and narrow shapes. Each port is 3.125 inches high and 1 inch wide in the measurement. Like the other LS series heads, unlike LS7, these cylinder heads are interchangeable among blocks. Of course, you need to pay attention to the potentiality of the valve to bore interference.

They have 11 mm head bolts in diameter. The head bolt length is 11mm × 100mm. Also, they feature extra 8mm× 1.25 × 45mm pinch bolts. These are situated at the inboard edge of the cylinder heads. Because of the long cylinder sleeves, the LS2 cylinder blocks are outstandingly great for stroking. An input of a 4-inch crack will make it a 408.

LS3 Short Review

This series came to the market in the year 2008. The performance level was really high and the power output jumped to 430 horsepower. Can you imagine? Particularly more power was given to the LS3 blocks. As a part of the evolution process, it was relaunched in the manually equipped cars in the year 2010.

The LS3 heads feature 6.2L of displacement. It is also a Gen lV engine of the Chevrolet. The intake ports are rectangular. The port is 2.550 inches tall and 1.250 inches wide. These engine heads are arrayed with tapered beehive valve springs. To learn more about the LS3 heads’ specifications, please read our ls3 vs ls7 article.

Difference Between LS2 & LS3

Now it’s time to decide the winner. No wonder both of them are developed with user-friendly features maintaining the standard of the LS series engines. Throughout the evolution of many years, they only got better and better with many additional specs and functionalities. But during our testing period, LS3 heads gave a better output than the LS2 heads.

If you bolt an LS3 head onto an LS2, you will get 20whp+. What more can you get after swapping your OEM parts. Furthermore, they have a better flow and greater power output than those of LS2. Also, they vary in the intake manifold, rockers, injectors, etc. To be more specific, bore size is a big difference between these two. While the LS2 features a 4.000″ bore, the LS3 features a 4.065″ bore. This additional .065″ has a great impact on the actual flow into the cylinder.

The block difference also impacts the structural strength. Although the LS3 will cost you more, yet the performance will make it up. But if you fall short of money, the LS2 is also a good option. But a limited budget will only provide some limited services. You have to accept it.  So, we highly recommended going for an LS3 cylinder head if you want to enjoy the ultimate benefits.

Final Words

Finally, though we recommend the LS3 as the race winner between LS2 VS. LS3, we cannot deny the adaptability range of LS2. That is why it is one of the most popular engine heads at a mid-budget range. But surely, LS3 gives a record-breaking performance. So, try to choose wisely considering your requirements as well as your allotted budget.

Frequently Asked Questions (FAQ)

Yes, LS3 heads can be used on an LS2 engine. This is a popular upgrade for those looking to increase the power and performance of their vehicle. LS3 heads offer increased airflow and higher lift camshafts, which can lead to significant gains in power. Additionally, they are compatible with all LS6 intake manifolds, making them a great option for those looking to upgrade their engine.
The LS3 engine features aluminum cylinder heads that are based on the L92 design. These heads feature larger intake and exhaust ports, as well as a higher compression ratio. The heads also feature Active Fuel Management, or AFM, which allows the engine to operate on four cylinders when under light loads to improve fuel economy.
There are a few key ways that you can tell an LS2 from an LS3. First, the LS2 will have round port heads, while the LS3 will have rectangular port heads. Additionally, the LS2 will have a cast aluminum intake manifold, while the LS3 will have an aluminum sheet metal intake manifold. Finally, the LS2 will have hydraulic roller lifters, while the LS3 will have solid roller lifters. By knowing these key differences, you’ll be able to easily identify which engine is in your vehicle.
As far as factory heads go, the LS3 heads are some of the best-flowing. They can flow up to nearly 290 cfm on the intake side and over 200 cfm on the exhaust side. However, keep in mind that these numbers will vary depending on the exact specifications of your engine. Customizations like porting and polishing can also affect airflow. Nevertheless, stock LS3 heads are capable of supporting big power builds. So if you’re looking to make some serious horsepower, don’t overlook these great factory heads!


LS2 Engine

LS3 Engine

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