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Kooks 1-7/8-Inch Long Tube Headers (11-14 Mustang GT)

Item 65511
AmericanMuscle no longer carries the Kooks 1-7/8-Inch Long Tube Headers (11-14 Mustang GT). Please check out 1979-1993 Foxbody Mustang Headers for an updated selection.
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    Video Review & Installation

    Hey guys, Stephanie with here with my review of these Kooks long tube headers, available for all 2011 to 2014 GTs and 2012 to 2013 Boss Mustangs. These Kooks long tube headers are going to be one of the top of the line options for the guys out there that are looking for a high quality long tube header for a more heavily modified car, or a car with forced induction or a nitrous car. The runners on these headers are one and seven-eighth inch which is slightly different than the one and three-quarter inch offering. The smaller diameter is traditionally going to be a better option for those naturally aspirated cars or those with mild bolt-ons. Just keep that in mind when you're shopping for long tubes. That doesn't mean you have to have a blower to run a one and seven-eighth inch diameter. You just need to keep in mind your current mods and the goals you have for your car when you're looking around, as well as what going with this size runner will do to your power band with the mods that you have. Kooks does offer these same headers with a one and three-fourth runner if you think those are more appropriate for you or you really only have some minor bolt-ons. Now these long tubes from Kooks are one of the nicer header options available for the modern Coyote motor, so they are going to be on the more expensive side of things. But you get what you pay for here. With all of that being said, we were able to get some Dyno results from these long tubes. Let's take a look so you can see what I'm talking about. We already ran a baseline run and got some numbers in the book. We're going to run the car again with the Kooks long tubes and Boss midpipe installed since we have a Boss Mustang here with us today. We did pair these mods with a VMP X4 tune because you will need a tune when you switch over to running long tubes. A tune here will not only help you get everything out of these expensive mods, but one of the main purposes of the tune with long tube headers is to turn off those rear O2 sensors so you won't be getting a check engine light.Our baseline run with a 2013 Boss gave us numbers of 398 horsepower and 337 foot-pounds of torque at the rear wheels. After installing the long tubes and midpipe and throwing the tune on the car, it made 417 horsepower and 353 foot-pounds of torque. That means a peak gain of 19 horsepower and 16 foot-pounds of torque, which are solid numbers considering the gains that you usually see from long tubes. Throughout the curve we're seeing gains of 23 horsepower at 6400 RPM which is what we expected to see, top end gains with the long tube headers. We also saw 26 foot-pounds of torque at 3500 RPM which is a nice torque jump in the lower RPMs. I always like to see low end torque gains because they're going to make a big difference in the driving experience. Overall, I'd say that these are solid curve gains that anyone should be happy with. Now a lot of these gains are from the long tubes and the tune, not necessarily the midpipe, but you can't run the long tubes without the midpipe.Getting into the specifics here, this is a 304 stainless steel header that has a natural or raw finish, which is going to be different than a chrome or ceramic coated header. It obviously does not have the polished appearance that a chrome header would have. And while these do not have the ceramic coating either, they are made from that 304 stainless steel tubing so you won't have to worry about corrosion. Not to mention you do get to see those beautiful welds since these have that raw finish. This is mandrel bent tubing, which is going to help with smoother air delivery. The headers are all TIG welded. The header flanges have a ball flange design that is leak free and gives an OEM fit as well as optimal performance. We are going to install these, so I can talk about the fit more later. You're also looking at Venturi style collectors here that have scavenger spikes that help with the exhaust flow. Scavenger spikes aren't surprising here. It's something that I expected to see from a quality header. I'm not disappointed. If you don't know already, when you change your header setup to a long tube setup you also need to change your midpipe to a shorty midpipe to work with the long tubes. These headers are specifically designed to work with a Kooks shorty midpipe. Like I said, we did install the headers as well as a midpipe on a Boss Mustang. Since this is a Boss Mustang, we had to choose a shorty midpipe that works for that car. Kooks offers a catted H-pipe for the Boss Mustang that we will be using. The H-pipe is a three inch midpipe that steps down to a two and three-quarters and still maintains that side exhaust. You may not necessarily be installing long tubes and a shorty midpipe for sound benefits, but the long tubes alone are going to change the sound of your exhaust. When you combine that with the midpipe swap you can expect a pretty big difference in sound at the end of the day. We did grab some sound clips so you can hear what these long tubes will sound like with both a factory cat back as well as an aftermarket cat back. Take a listen.If we move on to price, as we all know or you'd know if you've been shopping for long tubes, they're going to be a solid investment. They are pricey and difficult to install. The options from Kooks, since they are a high quality item that's more at the top of the food chain, are going to be on the more expensive side. The one and seven-eighths option that we have here are going to be slightly more expensive than the one and three-fourths version, but not by very much at all. You're looking at just over $1,000 for a set. Then you also have to keep in mind that these headers need that shorty midpipe I mentioned earlier which, depending on what car you have, a GT or a Boss, will cost anywhere from $500 to $600 for a Kooks X-pipe. Or about $750 for the H-pipe that we're going to install on the Boss. This is where the investment title that I gave this setup earlier comes from. You do have to keep in mind all of the benefits in power that you'll be getting from this setup. To put things in perspective, it's not just Kooks that's going to be expensive. You're going to be looking at headers costing over $1,000 if you're looking at going with the other big player like LTH anyways. At the end of the day you're looking at both power and sound gains here. You saw the gains from the Dyno. Keep in mind that these will change depending on your setup and tune. You do have a pretty good idea what you can expect there. In addition to that, you're also going to get an awesome change in your exhaust tone. As for the install on this one, long tubes are always going to be a difficult install. I don't say this often, but if you don't have a helping hand or don't have much experience it might be better to just take the car to a shop for the install. If you do tackle this yourself, it's going to be a full three out of three wrenches on the scale and a day in the garage, especially considering you'll be installing the midpipe with these headers. You can do it on a jack and stands, but a lift will certainly make it easier for sure. You're going to need your toolbox for this one with an assortment of different sockets, wrenches and extensions. You're looking at things like disconnecting the steering shaft, dropping the starter, and removing a motor mount. A lot of this install obviously requires working in some pretty tight areas. While everything is straightforward, getting access and maneuverability in these areas is actually tricky, which is why you need to pull the motor mount on one side so you can raise the motor slightly with a jack to give you some more room. Since these are the larger one and seven-eighths headers, when we did the install we did have to drop the K-member here to give us enough room on the driver's side. Having a helping hand in this case is really going to benefit you, especially considering the weight of the K-member. The steering box is going to make it really heavy. But a day of wrestling and some pretty pennies spent on these mods is totally worth it in my opinion. Wrapping things up here, the Kooks long tube headers are one and seven-eighths diameter. They're designed to work with a Kooks shorty midpipe. They're going to offer both performance and sound gains. This option is a little on the more expensive side, but Kooks gives a full stainless steel high quality product. You can check them out more online for yourself right here at

    Product Information

    Features, Description, Reviews, Q&A, Specs & Installation


    • Increases RWHP and Torque
    • Long Tube Header Design
    • Free Flowing 1-7/8" Mandrel-Bent Tubing
    • 304 Stainless Steel Construction
    • TIG Welded for Strength
    • Fits 2011-2014 GT Mustangs


    More Horsepower and Torque. A set of Kooks Long Tube Headers will greatly improve the performance of your 5.0L Coyote Mustang. Kooks Headers feature an integrated venturi style collector that increases exhaust scavenging, and reduces turbulence to improve your 5.0's exhaust flow over the restrictive factory manifolds, boosting your Pony's horsepower and torque numbers.

    Quality Construction. Kooks Long Tube Exhaust headers are manufactured from 1-7/8" mandrel bent 304 stainless steel tubing for superior airflow. These headers are TIG welded and feature a leak-free ball flange design for optimal performance and a better than OEM fit.

    Recommended Upgrade. To realize the full power potential that these Long Tube Headers have to offer, AmericanMuscle recommends a custom tune with a Mustang Handheld Tuner to reprogram the vehicles computer (ECU) for proper operation.

    Application. These Kooks Long Tube Headers are designed to fit the 2011-2014 5.0L GT Mustangs. Kooks long tube headers require the use of a Kooks shorty midpipe in order to be installed properly (see drop down option above).


    Technical notes. Not legal for use on pollution controlled motor vehicles; intended for off road use only.

    CA Residents: WARNING: Cancer and Reproductive Harm -

    Installation & What's in the Box

    Installation Info

    What's in the Box

    • (1) Driver side header
    • (1) Passenger side header
    • (2) Gaskets
    • (16) Small bolts
    • (8) Flat washers
    • (4) Long bolts
    • (4) Nuts

    Tech Specs

    Header Specifications
    Header Type: Long Tube Finish : Natural
    Type Mid Pipe Required: Shorty Fitment: 2011-2014 5.0 GT Mustangs

    Customer Reviews (83)

      Questions & Answers

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