Description

Kooks S650 Mustang GT & Dark Horse Long Tube Header Kit With Green Cats — RHD Specific Fitment (2024+)

The Only Long Tube Headers Built Specifically for Right-Hand Drive S650 Mustangs

If you own a right-hand drive S650 Mustang GT or Dark Horse and you’ve looked into long tube headers, you’ll already know the problem — virtually every header kit on the market is designed for the left-hand drive US market. The routing, the clearances, and the O2 sensor positions are all wrong for a UK-spec car. Fitting LHD headers to an RHD Mustang is either impossible or requires serious fabrication work that nobody should be paying for on a £3,500 exhaust upgrade.

These Kooks headers are different. They are engineered specifically for the right-hand drive S650 Mustang platform, developed in collaboration with MAP to solve exactly this problem for UK and European owners. Everything fits correctly first time — the primaries route correctly around the RHD steering rack, the O2 sensor positions are in the right place, and the collectors exit cleanly to connect with your cat-back system.

Long tube headers are the single biggest naturally aspirated power unlock available for the Coyote 5.0L. They replace the most restrictive part of the factory exhaust path — the manifolds — and when combined with a custom tune deliver a transformation in mid-range torque, top-end power, and exhaust note that no other bolt-on modification can match. These are the headers fitted as part of our Stage 3 NA Package, which delivers 530–550 bhp from the stock engine.

Why Kooks

Kooks Custom Headers have been building race-grade exhaust headers in the USA for over 60 years. Every set is handcrafted from T304 aircraft-quality stainless steel using mandrel bending to maintain consistent tube diameter through every bend, maximising exhaust flow at every engine speed. The 3/8″ thick laser-cut flanges ensure a leak-free seal at the head, and Kooks’ patented scavenging spikes in the 3″ collectors actively accelerate exhaust gas velocity to improve cylinder scavenging. This is not off-the-shelf fabrication — it is purpose-built performance engineering.

High-Flow Green Catalytic Converters

This kit includes Kooks’ high-flow Green Cat converters — 400-cell catalytic converters designed to handle up to 600 BHP without triggering fault codes or causing the engine management system to enter limp mode. They flow significantly more than the factory catalysts while retaining catalytic converter function, keeping the system compliant and your dashboard warning-light free.

Technical Specifications

• Primary Tube Diameter: 1-3/4 inch mandrel-bent
• Collector Size: 3 inch with Kooks Patented Scavenging Spikes
• Flange Thickness: 3/8 inch laser-cut
• Material: T304 Aircraft Quality Stainless Steel
• Catalytic Converters: High-Flow 400-cell Green Cats
• Fitment: RHD specific — 2024+ Ford Mustang GT and Dark Horse (S650)
• Kit Includes: Headers, Green Cat converters, gaskets, O2 sensor extension harnesses, clamps, and all required mounting hardware

Lead Time

Kooks headers are built to order to ensure premium quality and correct RHD fitment. Please allow 6–10 weeks from order for your headers to be produced and delivered. We will keep you updated throughout and confirm your workshop installation slot as soon as your kit arrives. If you are purchasing these as part of our Stage 3 NA Package, lead time is factored into your booking automatically.

Vehicle Compatibility

• Model: Ford Mustang GT and Dark Horse (S650)
• Drive: Right-Hand Drive only
• Years: 2024+
• Engine: 5.0L Coyote V8

Frequently Asked Questions

Why do I need RHD-specific headers for my UK Mustang?
The S650 Mustang in right-hand drive configuration has different engine bay geometry to the LHD version — primarily around the steering rack position. Standard US-market long tube headers cannot be fitted to an RHD car without significant modification. These Kooks headers are engineered specifically for the RHD platform, routing correctly around the steering rack and positioning the O2 sensors in the right locations for a clean, leak-free installation.

Will these headers require a tune?
Yes. Long tube headers change the exhaust characteristics significantly and a custom ECU tune is required to get the full benefit and avoid fault codes from the O2 sensors. The kit includes O2 sensor extension harnesses to maintain sensor function, but a tune is still necessary. We offer a full installation and custom dyno tune service — our Stage 3 NA Package includes these headers along with a JLT intake, BMR engine mounts, and a bespoke MAP tune for 530–550 bhp.

Will these throw engine management fault codes?
The included high-flow Green Cat converters are designed to maintain catalytic converter function and prevent the downstream O2 sensors from triggering fault codes. Combined with a proper tune, the car will run cleanly without warning lights.

How much power will long tube headers add?
On their own with a tune, long tube headers typically add 30–50 bhp on a stock S650. As part of our full Stage 3 NA Package — which also includes a cold air intake and engine mounts — the combination delivers 530–550 bhp from the stock Coyote V8, compared to around 444–450 bhp at the wheels in stock form.

Will these work with my existing cat-back exhaust?
Yes. The 3″ collectors are designed to connect to standard cat-back exhaust systems. Whether you have a factory exhaust or an aftermarket cat-back from Borla, Ford Performance, or another brand, these headers will connect cleanly. Get in touch if you want to confirm compatibility with your specific setup.

Can MAP fit these for me?
Yes — and we’d strongly recommend it. Long tube header installation on the S650 is a significant job that requires specialist knowledge, particularly on the RHD variant. We carry out all installations at our workshop in Batley, West Yorkshire, and every car is tuned live on our in-house rolling road before it leaves. Our Stage 3 NA Package includes these headers with full installation and tune — see the related products below.

Why is the lead time 6–10 weeks?
Kooks builds every set of headers to order rather than holding shelf stock. This ensures every kit is produced to the correct specification for your specific vehicle. The RHD S650 fitment is a specialist build that Kooks produces in batches — we will keep you updated on progress and confirm your workshop slot as soon as your headers arrive.