Next Level Performance
August 1, 2026 • 11 min read
Our Verdict
For the 640 hp LT4 CTS-V, the Stainless Works 2016-2019 2in long-tube headers with catted X-pipe leads are the best all-round pick — the largest primaries in this group, an integrated X-pipe, and a lifetime warranty.
Building a 2009-2015 LSA car instead? The Stainless Works 2009-2015 set is the direct equivalent, offered in a factory-connect or Stainless-Works-cat-back-connect version. Kooks is the pick if you want a proven 1-7/8in longtube with GESI green catted connection pipes.
Shop Our Top Pick →Long-tube headers are the single biggest bolt-on for a supercharged Cadillac CTS-V, and the right set of Cadillac CTS-V headers can unlock 15 to 30 rear-wheel horsepower on a tuned car while dropping intake air temperatures and shedding weight over the restrictive cast manifolds. The catch is fitment: the 2009-2015 second-generation car runs a 556 hp supercharged LSA V8, while the 2016-2019 third-generation sedan runs the 640 hp LT4 — and the headers are not interchangeable. This comparison puts the four best long-tube header kits we stock for the CTS-V head to head, covering primary tube sizing, catted connection design, gains, install time, and exactly which model year each one fits.
Why Long-Tube Headers on a Supercharged CTS-V?
Long-tube headers replace the CTS-V’s heavy, restrictive cast-iron exhaust manifolds with equal-length, mandrel-bent stainless primary tubes that merge into a 3-inch collector. On the supercharged 6.2L V8, that does three things at once: it reduces exhaust backpressure so the Eaton blower moves air out of the cylinders more efficiently, it improves scavenging across the mid-range, and it cuts underhood heat soak — a real benefit on a positive-displacement supercharged engine where intake air temperature directly limits power.
On a naturally aspirated LS car, long-tubes are worth big percentage gains. On a blown LSA or LT4 the percentage is smaller, but the absolute numbers are still substantial because the engine is already moving so much air. In our Tampa shop, a tuned CTS-V running long-tube headers, high-flow cats, and a matching cat-back typically picks up 15 to 30 rear-wheel horsepower and a similar torque figure, with the biggest gains showing up from 3,500 rpm to redline. Headers also drop several pounds of nose weight versus the cast manifolds and open the door to future upgrades like a smaller supercharger pulley or a ported blower.
Kooks 1-7/8in x 3in 304 stainless long-tube headers with green catted connection pipes.
Cadillac CTS-V Long-Tube Headers Compared
Every kit below is a full-length long-tube design in 304 stainless steel with high-flow catalytic converters, so all four stay street-friendly in most states while cutting restriction. The decisive differences are which generation they fit, primary tube diameter, and how they connect to the rest of the exhaust. Prices reflect current NLP Performance pricing.
| Kit | Fits | Primaries | Connection | Price |
|---|---|---|---|---|
| Stainless Works CTS-V Headers (Gen 3)Top Pick | 2016-2019 LT4 | 2 in | 3in catted leads into X-pipe | $2,965.50 |
| Kooks LT4 Longtube Headers | 2016-2019 LT4 | 1-7/8 in | Green catted connection pipes | $2,687.51 |
| Stainless Works CTS-V Headers (Gen 2, Factory Connect) | 2009-2015 LSA | 2 in | High-flow cats, factory connect | $2,515.50 |
| Stainless Works CTS-V Headers (Gen 2) | 2009-2015 LSA | 2 in | High-flow cats, SW cat-back connect | $2,245.50 |
The Four Best CTS-V Header Kits, Reviewed
The most complete kit here for the third-gen car. Stainless Works pairs 2-inch primaries — the largest in this comparison — with 3-inch catted leads that flow straight into an integrated X-pipe, so you get the header and the mid-pipe crossover in one package. That larger primary favors the LT4’s top-end, where the 640 hp engine wants every bit of flow it can get. It is the priciest option, but it is also the only one that includes the X-pipe, and it carries a lifetime warranty against defects.
Kooks is the header brand of choice for a lot of serious LS and LT builders, and this kit shows why: CNC-machined 3/8-inch flanges, fully TIG-welded 304 stainless, and green catted connection pipes using high-efficiency GESI-style catalytic converters to keep the check-engine light off with a proper tune. The 1-7/8-inch primaries are slightly smaller than the Stainless Works set, which can help preserve exhaust gas velocity and low-end response on a street-driven LT4. Note that it does not include an X-pipe, so budget for a compatible mid-pipe or cat-back.
Stainless Works uses 2in primaries and 3in collectors in 304 stainless for the LT4 CTS-V.
This is the second-gen equivalent of our top pick and the right call if you plan to keep your factory exhaust behind the headers for now. The factory-connect version bolts the 2-inch primaries and high-flow cats up to the stock mid-pipe and mufflers, so you can add headers today and a cat-back later. It is the value sweet spot for a 556 hp LSA car that is still mostly stock downstream.
The most affordable kit in the group and the one to buy if you are going full Stainless Works front to back. It is built to connect to a Stainless Works cat-back rather than the factory exhaust, so it makes the most sense as part of a complete exhaust package on the 2009-2015 LSA car. Same 2-inch primaries, same high-flow catted design, same lifetime warranty as its factory-connect sibling.
Top Pick Key Specs — Stainless Works Gen 3
What We Like (Stainless Works Gen 3)
- + Largest 2in primaries in the group for LT4 top-end flow
- + Integrated 3in catted leads and X-pipe in one kit
- + Lifetime warranty and 304 stainless construction
Things to Consider
- – Highest price in this comparison
- – Requires a custom tune to clear cat and O2 codes
Gen 2 LSA vs Gen 3 LT4: Which Headers Fit Your CTS-V?
CTS-V headers are generation-specific, and buying the wrong set is the most common mistake we see. The second-generation CTS-V (2009-2015) uses the 6.2L supercharged LSA V8 rated at 556 horsepower and 551 lb-ft, sold as a sedan, coupe, and wagon with a six-speed manual or automatic. The third-generation CTS-V (2016-2019) is sedan-only and runs the LT4 6.2L supercharged V8 — the same basic engine family as the C7 Corvette Z06 — rated at 640 horsepower and 630 lb-ft through an eight-speed automatic.
Because the LT4 uses a different block architecture, cylinder head port shape, and chassis packaging than the LSA, the headers do not cross over. For a 2016-2019 car choose the Stainless Works Gen 3 or Kooks LT4 kit; for a 2009-2015 car choose one of the two Stainless Works Gen 2 sets. If you own an LSA car and are not ready to replace the whole exhaust, the factory-connect Gen 2 kit lets you add headers now and keep the stock cat-back until you upgrade.
The Gen 2 Stainless Works kit fits the 556 hp LSA CTS-V and offers a factory-connect option.
Stainless Works vs Kooks: Build Quality and Power
For the 2016-2019 LT4 car, the real decision is Stainless Works versus Kooks. Both are 304 stainless, both are fully TIG-welded long-tubes, and both use high-flow catted connection pipes rather than an off-road design, so both keep a tuned car emissions-friendlier and quiet enough to live with daily. The differences are primary sizing and packaging.
Stainless Works runs 2-inch primaries and bundles the 3-inch catted leads with an X-pipe, giving the LT4 maximum top-end flow and a complete mid-section in one box — ideal for a car chasing peak horsepower with a pulley and tune. Kooks runs slightly smaller 1-7/8-inch primaries with green GESI-style catted connection pipes and is renowned for fit and finish, with thick CNC-machined flanges that resist warping under the LT4’s heat. The smaller Kooks primary can sharpen throttle response and low-end torque on a street car, while the larger Stainless Works tube shades it up top on a built engine. Either way, plan on a supporting tune to realize the gains and clear diagnostic codes.
Installation, Tuning, and Emissions
Long-tube headers are one of the more involved bolt-ons on the CTS-V. Expect 8 to 12 hours on a lift; the job typically involves unbolting the steering shaft and dropping or shifting engine mounts to snake the primaries past the chassis. Because of the labor and the tight packaging around the supercharged V8, we recommend professional installation unless you have a lift and experience with LS/LT swaps.
A custom tune is not optional. All four kits retain catalytic converters, but you still need a calibration (HP Tuners is the standard on these cars) to correct fuel and spark for the freer-flowing exhaust and to prevent rear O2 catalyst-efficiency codes. High-flow cats keep these kits street-oriented, but they may not be CARB-legal in California or other states with strict emissions enforcement — verify local requirements before buying. To get the full benefit, pair the headers with a complete exhaust and intake: on the LT4 car, the Stainless Works CTS-V cat-back or the Borla S-Type cat-back with valves matches the 3-inch header outlet, and an Airaid performance intake feeds the blower more air on the LSA car.
An Airaid intake pairs with long-tube headers to feed the supercharged CTS-V more air.
Frequently Asked Questions
How much horsepower do headers add to a Cadillac CTS-V?
Long-tube headers add roughly 15 to 30 rear-wheel horsepower on a tuned supercharged CTS-V, with the gains concentrated from 3,500 rpm to redline. The exact figure depends on the rest of the build; headers paired with high-flow cats, a matching cat-back, and a proper tune sit at the top of that range, and adding a smaller supercharger pulley pushes it higher.
Do CTS-V headers require a tune?
Yes. All four kits in this comparison require a custom tune, typically done with HP Tuners, to correct fuel and spark for the reduced backpressure and to prevent rear O2 catalyst-efficiency codes. Even though every kit retains high-flow catalytic converters, the ECU still needs recalibration to run correctly and realize the power gains.
Will 2009-2015 CTS-V headers fit a 2016-2019 model?
No. The 2009-2015 CTS-V uses the supercharged LSA V8 and the 2016-2019 CTS-V uses the LT4 V8, which has a different block, head ports, and chassis packaging. Headers are generation-specific: choose the Stainless Works or Kooks LT4 kit for a 2016-2019 car, and the Stainless Works Gen 2 kit for a 2009-2015 car.
Stainless Works or Kooks headers for the LT4 CTS-V?
Choose Stainless Works if you want the largest 2-inch primaries and an integrated X-pipe for maximum top-end power on a built LT4, or Kooks if you prefer 1-7/8-inch primaries with green catted connection pipes for slightly sharper low-end response and its renowned CNC-machined fit and finish. Both are 304 stainless, fully TIG-welded, and street-friendly with a tune.
Are CTS-V long-tube headers street legal?
These kits use high-flow catalytic converters, so they are designed to stay street-friendly in most states and keep the check-engine light off with a proper tune. However, high-flow cats are not guaranteed to be CARB-legal in California or other states with strict emissions testing, so confirm your local requirements before purchasing.
How long does it take to install CTS-V headers?
Plan on 8 to 12 hours on a lift. The install usually requires unbolting the steering shaft and repositioning engine mounts to route the primary tubes past the chassis around the supercharged V8. Because of the labor and tight packaging, professional installation is recommended unless you have a lift and LS/LT experience.
Ready to Wake Up Your CTS-V?
Shop long-tube headers, cat-backs, and supporting mods for the LSA and LT4 CTS-V at NLP Performance.
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