Key Takeaways

  • The LS1 was the first engine with an aluminum block produced by General Motors.
  • The LS3 engine has a bigger displacement, more peak power, and a higher compression ratio than the LS1.
  • The newer engine (LS3) is considered more reliable and makes better engine noise.
  • A car enthusiast may want to perform an LS swap with an original small block.  

This post may include affiliate links. If you make a purchase through these links, we'll receive a commission at no extra cost to you. This support helps us maintain and grow our site. Thank you for your support!

If you are a Chevy lover, you probably know about the LS engine family. But what is the difference between LS1 vs LS3? Let’s take a look at each.

The LS family of V8 engines, which GM labeled as the Generation III Small Block, debuted in 1997. The LS1 engine was a 5.7 V8 with 345 hp and 350 lb/ft of torque. The LS3 was a 6.2L V8 (fourth generation) produced for the ‘08 Corvette. It produced 430 hp and 424 lb/ft of torque.

Every classic car lover knows that the V8 engine is the only way to go if you want real power for a rebuild. While plenty of V8 engines were made during the last hundred and twenty years of automotive history, the LS family of Chevy small blocks is consistently rated as one of the best. The Gen 3 small block debuted as a 5.7 L V8 for the 1997 Corvette, but in 2008, GM perfected the small block to release the LS3 (Gen IV engines) with a significant bump in both power and performance. What is the difference between the LS1 and the LS3 engines? Which is the better engine? If you aren’t already familiar with these two excellent engines, let’s take a moment to examine them. But first, a little bit of history might be in order.

Table of Contents

What Is the History of the LS1?

When GM introduced the LS engine for the 1997 Corvette, they knew they were working in new territory. As the first V8 to use an all-aluminum block, the engine was designed to weigh nearly 88 pounds less than its predecessor. The weight reduction was significant, providing increased strength and power for the powerplant and a way to faster times on the track.

When it was first released as a 5.7 L V8, GM needed a new engine for the new fifth generation of the Corvette. The new hydroformed frame improved the structural stability of the car, and while the engine produced only 345 hp when it was paired with the new Borg Warner T56 six=speed manual, the new Corvette pushed a 4.5 second 0 - 60 and redlined at 175 mph at its top speed.

It wasn’t long before the new Gen III engine found its way into other vehicles like the ‘98 - 2002 Pontiac TransAm, Firebird, Chevy Camaro Z28, and SS models. It also made an appearance in the ‘04 Pontiac GTO.

The LS1 had significant changes because it used electronic ignition, using a modified ECU to control firing rather than old-fashioned distributor caps. The multi-port injection allowed the engine to be tuned more precisely than predecessors, resulting in better efficiency and fuel economy while producing better thrust during higher rpms.

The LS1 morphed into several variants, including the LS6 ('01-'04 Z06), LS2 ('05-'07 C6 Corvette), and LS7 ('06-'13 Z06). In 2001, the engine was tweaked for a small bump in power (to 350 hp), but the engine was a radical departure from V8 engines of the past and set General Motors on the path to building better LS engines with increasingly more power.

When Did the LS3 Come Into Play?

The LS3 debuted in 2008 as a part of GM’s Generation IV engines. The 6.2 L V8 was a serious upgrade for the Corvette (C6), producing 430 hp and 424 lb/ft of torque. The old T56 transmission was dropped in favor of a TR6060, which provided improved shift links and helped power the C6 to a 0-60 mph time in just over 4.0 seconds (which was faster than any production Corvette made up to that time).  

The LS3 was produced for the '08-'13 Corvette and Corvette Grand Sport (although it was a modified version with dry sump oil cooling and a unique forged steel crankshaft). A year after it was first introduced, the versatile engine made its way into the ‘10 - ‘15 Camaro SS and Convertible and made its final bow as a part of the 2015 - 2017 Chevrolet SS (which was produced in Australia as a Holden Commodore VF and imported into the states).

What Are the Differences Between the LS1 and LS3?

While both engines have aluminum blocks, share similar components, and produce impressive results, they are very different. The following sections list some primary characteristics that differ between LS1 and LS3.

The Displacement And Bore Are Different

The primary difference is the displacement of the LS1 at 5.7 L  (346 ci), and the LS3 was 6.2 L (376 cubic inches). The LS3 has a larger bore (4.065), while the LS1 has a bore diameter of 3.898. While both engines have the exact stroke figure (3.622 inches), the compression ratios differ. The compression ratio for the original LS1 was 10.2:1, while the LS3 had rectangular port heads and comp ratios of 10.7:1.

Fuel Injector Size and Flow

The LS1 used longer fuel injectors with a smaller spray pattern than the LS2 and LS3 engines. The flow rates are unique to each engine, with the LS1 having 255 liters per hour, while the LS3 is significantly more generous (375 liters per hour). The demand for a higher power output of the LS3 demanded a more consistent fuel flow.  

Intake Ports and Runner Values

While the LS1 had aluminum heads with different intake ports (cathedral vs rectangular). While the LS1 had significantly smaller combustion chambers, you would expect this since the LS1 is the smaller engine. The power difference between the LS1 and LS3 is a direct result of these differences.

Intake Manifolds

While the intake manifolds from the first LS1 Corvette were made with different port settings than the LS3, which GM increased in size and straightened the high flow intake manifold to provide better airflow to the engine. The LS1 engines operated with a cable and LS3 had drive-by-wire. Generally, due to the difference in size and bolt pattern, the intakes cannot be swapped between engines without significantly changing the cylinder heads.


The older LS1 engine is priced significantly cheaper than, the newer LS3. While prices can vary, the nominal cost of the LS1 engine will run between $3k - $5k (although auctions or junkyards may have remans for less).

A standard LS3 will cost between $7 - 8k, depending on the mileage. GM does offer the LS3 as a crate engine, but the price for a new engine is quite expensive, over $10,000.

What Are The Specs of the LS1 and LS3?

The following chart provides many of the basic specs of the LS1 vs. LS3 engines.

Item 5.7 LS1 V8 (1997) 6.2L LS3 V8 (2008)
Generation LS1 (Gen III) LS3 (Gen IV)
Production Years 1997 - 2004 2008 - 2017
Aspiration Natural Natural
Block Aluminum Aluminum
Cylinder Heads Aluminum Aluminum
Intake Port Design Cathedral-shaped Rectangular-shaped
Intake Runner Volume 200 cc 257 cc
Exhaust Runner Volume 70 cc 87 cc
Displacement 5.7 Liters 6.2 Liters
Cubic Inches 346 cu. In. 376 cu. In.
Horsepower 345 - 350 hp @ 5600 rpm 430 hp @ 5900 rpm
Torque 335 - 365 lb/ft @ 4400 rpm 424 lbs/ft @ 4600 rpm
Bore Size 4.0 inches 4.065 inches
Stroke 3.62 inches 3.62 inches
Compression 10.2:1 10.7:1
Firing Order 1-8-7-2-6-5-4-3 1-8-7-2-6-5-4-3
Oil Pan Interchangeable Yes Yes
Intake Manifold 74 mm - 3 bolt 76 - 90 mm 3 or 4 bolt
Cost $3 - 5k $6 - 8k
Transmission T56 six-speed
4-speed automatic
TR6060 six-speed
6-speed automatic

What Problems Did the LS1 and LS3 Have?

While the LS series engines were reliable and dependable, the LS1 and LS3 engines share some issues.

LS1 Issues

Some of the more common issues with the LS! Engine ranged from water pump failures, bent pushrods, and bad piston ring seals. The OEM oil pump had issues keeping up when the vehicle was pushed to higher rpms (above 6,000).

LS3 Issues

The more significant displacement of the LS3 could lead to some of the overheating issues that could plague the earlier motor, and it also tended to drink oil like nobody’s business. Excessive oil consumption often leads to lifter problems. Water pump issues and failed pushrods were also issues that car enthusiasts have documented over the years.

Which is the Better Motor - The LS1 Or The LS3?

Due to technological advances during the early 2000s, the LS3 is considered the more reliable of the two engines. While both engines can be easily modified for increases in power and performance, care must be taken when using aftermarket parts to ensure that they fit.

LS1 Vs LS3 (List Of Differences)

About The Author

Charles Redding

Charles Redding

I've spent many years selling cars, working with auto detailers, mechanics, dealership service teams, quoting and researching car insurance, modding my own cars, and much more.

Read More About Charles Redding