Chevy LS2 Headers Upgrade Guide

GM/Chevy first introduced their glorious LS2 V8 engine in 2005, putting it in models like the C6 Corvette, Pontiac GTO, and SSR truck. Within a few years, they started putting versions of the LS2 inside a wider range of applications. While 300-400 horsepower from the factory certainly isn’t slow, the LS2 has so much more potential. One of the top mods for LS2-powered cars, trucks, and SUVs is swapping out the stock exhaust for a set of headers. Upgraded LS2 headers will add horsepower and torque, improve throttle response, and really unlock the GM/Chevy 6.0 L engine. Of course, it’ll also really let the LS2 roar much louder than before.

This guide will cover the top options for upgrading your LS2 headers. We’ll take a look at the most well-reviewed and well-respected LS2 headers within the GM/Chevy community, and analyze them by cost, performance, and craftsmanship.

Header Basics

Headers are the part of an exhaust system that attaches directly to the exhaust ports on the LS2 engine. From the factory, they are typically called exhaust manifolds, and the term headers indicates something aftermarket. Enthusiasts use them when looking to increase the power output of their LS2 engine.

Headers collect the hot exhaust gasses as they are pushed out of the engine and direct them through the rest of the exhaust system. Due to being bolted directly to the engine, design and construction are incredibly important to prevent leaks and cracking. For stock power levels and applications, the OEM exhaust manifolds are capable of adequate performance. However, for anyone looking to increase their performance or get the most out of their other bolt-ons, aftermarket headers become very useful. Aftermarket headers are usually made from 304 stainless steel and have wider diameter piping than stock exhausts.

You want headers that provide good flow with as little turbulence as possible, while reducing weight over the stock exhaust. Exhaust gas turbulence is created by poorly thought-out designs that introduce large inopportune bends and joints, which impede flow. This diminishes the effectiveness and leads at times to reversion.

Reversion is a phenomenon where hot exhaust gasses are pushed back into the combustion chamber, robbing the engine of clean and cool air. A good header should open the exhaust flow, while reducing overall weight and exhaust gas temperatures and eliminating reversion.

Long-tube vs Short-tube Headers

There are two types of aftermarket headers that are commonly available for the LS2 engine, long-tube headers and short-tube headers. As their names suggest, the primary difference between the two of them is their length. Long tubes extend much further back than the short tubes (also called shorties) and usually either remove the catalytic converters or come with high-flow cats. Short tubes keep the cats in place, but we’ll get into more on that below.

Long-tube headers will undoubtedly offer better overall performance gains than short-tube headers, particularly in the mid-range and top-end of the power band. Short-tube headers will help with performance on the low-end, but at the expense of top-end power. They also produce less overall power than long-tubes everywhere in the power band. The best shorty headers will probably still be outperformed by low-quality long-tube headers.

Catted vs Catless Header Considerations

One of the most important decisions you will have to make when picking out LS2 headers is catted or catless. The stock exhaust system has two catalytic converters located very close to the stock exhaust manifold. The purpose of catalytic converters is to reduce emissions from the engine which contribute to climate change. However, catalytic converters also impede exhaust flow, meaning they reduce horsepower.

Short-tube headers only replace the area between the engine and the cats, whereas long-tube headers also replace the area with the stock cats. Some long-tubes have high-flow cat replacements built in, while others are completely catless.

If you do not want to touch your cats, then short-tube headers are your only option. If you are okay with either removing them or switching to high-flow cats, long-tube headers are the better option. As we stated, long-tube headers will give you the best performance, even if they are catted.

For most people, the best middle ground is going to be long-tube headers with high-flow cats. These still wake up the engine and increase horsepower, but they also stay legal for the most part.

Catless Headers Legality

An important consideration is legality. Removing your catalytic converters is a violation of many state and local laws, and can also run afoul of the EPA’s Clean Air Act. Catless exhausts are not street legal in the vast majority of the U.S. due to state emissions laws. This does not apply to vehicles that are strictly used at the race track.

Catted long-tubes will generally pass the sniffer test for emissions, and in many places are considered street legal for use. However, there are also some state (namely California) and local laws that prohibit any change to the cats, meaning even high-flow versions will not pass visual inspection. Make sure you consult and follow all applicable local, state, and federal laws before committing to any specific headers.

GM/Chevy LS2 Header Upgrade Benefits

Most enthusiasts looking at header upgrades are concerned with power gains, but there are several other benefits as well.

• +5-30 horsepower
• +5-25 lb-ft of torque
• Reduced back pressure & reversion
• Lower exhaust gas temperatures (EGTs)
• Improved exhaust scavenging
• Louder/Improved exhaust tone and volume

A pair of long-tube headers will net gains of about 15-30 horsepower by themselves. You can expect about a 5-horsepower difference between catted and catless versions. Shorty LS2 headers will gain 5-15 horsepower.

One of the biggest advantages of header upgrades is reduced back pressure and increased scavenging effectiveness. OEM headers are less effective outside of stock power levels and are usually made with cast iron. Aftermarket headers are purposefully designed to weigh less, reduce back pressure, and increase scavenging at higher than factory power levels.

Reducing back pressure lowers EGTs and increases scavenging, which both have several benefits. Keeping EGTs down prolongs engine life and keeps performance high. Increased scavenging and reduced reversion means the dirty exhaust gasses are removed and clean air can enter the combustion chamber. Which leads to bigger and more sustained power.

Of course, you’ll also hear a very clear audible difference in your car, truck, or SUV from installing new headers. Short tubes won’t be as loud as long-tubes, but will produce a noticeable difference. Long-tubes will raise your decibel level by several points, with catless exhausts being louder than catted. The volume will be louder, and the tone will also get deeper and more aggressive from catless long-tube headers on the LS2.

X-pipe vs H-pipe

If you are going with LS2 long-tube headers, you will have to choose between either an x-style mid-pipe or h-style mid-pipe. The difference is with the h-style pipe, the two headers never intersect and stay completely independent. On x-style mid-pipes, the headers will merge together before splitting off again for dual mufflers.

X-style pipes outperform the h-style pipes, but only barely. The x–style does allow for increased flow, but has shown to only translate into maybe 5 horsepower at the most. H-pipes generally allow for better low-end performance, while x-pipes tend to make a difference at the top of the power band. X-pipes also sound more high-pitched than the more traditional hot-rod-sounding h-pipes.

The more popular option tends to be the x-pipe, but it really comes down to personal opinion. Since sound is one of the biggest factors, you’ll probably want to hear both of them to make a good comparison.

Top 4 GM/Chevy LS2 Headers

Now let’s get into the top LS2 headers. This list is far from an exhaustive list of header upgrades. There are tons of great options that are just too numerous to list. Make sure to keep in mind that fitment will vary by year, make, and model. Always double-check fitment before purchasing any headers.

We’ve tried to focus on headers that are applicable to as many GM/Chevy models and years as possible. We’ve listed both long and short-tube headers that offer the best balance of price, quality, fitment, and performance. Keep in mind that most LS2 headers will need a custom exhaust back to the muffler as they won’t fit the stock pipes.

• American Racing Headers
• Stainless Works
• Kooks Headers
• Texas Speed and Performance

Headers Are a Great Upgrade Option for the LS2 V8

The GM/Chevy LS2 is an incredible engine, but it is capable of so much more performance than it is setup with from the factory. Just adding a good set of headers will really wake up the LS2. You’ll see gains in power and performance, and you’ll be able to hear the mighty LS2 roar at the top of its lungs. Expect to get 15-30 horsepower from long-tubes, and 5-15 horsepower from short-tubes on the GM/Chevy 6.0 V8.

We looked at some of the top options available on the market, including options from American Racing Headers, Stainless Works, Texas Speed and Performance, and Kooks Headers. Of all of them, we’d probably go with the ARH due to their quality, but if you’re on a budget the Kooks are hard to pass by. Either way, any of these headers will definitely be solid choices.

What’s your experience with LS2 headers? Are you considering any?

Leave a comment and let us know!