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Ford Performance Turbo-Swirl GT40X Aluminum Head; 58CC Chamber (82-85 5.0L; 87-95 5.0L)

Item 50542
AmericanMuscle no longer carries the Ford Performance Turbo-Swirl GT40X Aluminum Head; 58CC Chamber (82-85 5.0L; 87-95 5.0L). Please check out 2015-2022 Mustang Cylinder Heads & Valvetrain Components for an updated selection.
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    Video Review & Installation

    Hey guys, Stephanie from Here with the review of the Ford performance GT40x aluminum heads with the 58 CC combustion chambers for 1982-85 and 1987-95, 5 liter Mustangs. The Ford performance turbo swirl heads with the 58 CC combustion chambers are going to be for the 5 liter owners out there that are looking for a fully assembled aluminum head with a smaller combustion chamber in order to keep a higher compression ratio. The turbo swirl heads offer a ton of upgrades over the factory set up and the heads are the main component that flow air and fuel in and exhaust gases out, so they have a big impact on performance. There's a lot to go over here with these heads, but picking which cylinder head to add to your build isn't an easy task. Bigger isn't always better. You wanna choose the head that will be best for your application and your build. These heads not only have improved air flow over your factory heads, but they also have improved air flow over the original GT40 heads. If we look at the main components of the head, we're going to look at the combustion chamber first and its' volume.These particular heads have 58 CC combustion chambers. The volume of the combustion chamber is tied to the compression ratio and displacement, which is tied to horsepower. A larger chamber means larger displacement. A smaller chamber will increase the combustion ratio because you're compressing the same amount of air in a smaller space. If we compare these heads to the other Ford performance offering, these heads have 58 CC chambers, while the other option has a 64 CC chamber. That means that these heads which flow the exact same amount as the other Ford performance heads, will give a higher compression ratio, all other things equal. That's something that you want to keep in mind when you're planning your build. The next thing I'll talk about is the intake ports and then the exhaust ports. The intake ports are fed air and fuel through the intake port runners, and each port will match up to an intake or an exhaust belt. Of course, larger ports can flow more, and these heads have an intake port volume of 178 CCs and exhaust port volume of 62 CCs. What you usually want to do when you're picking out a set of heads, is to match your intake port type on the cylinder head to an intake manifold with a similar shaped port because the air is going to flow through the intake to the ports on the heads and you want smooth airflow here. That being said, just make sure you have the manifold lined up that'll work well with these heads. As far as the exhaust ports, you're going to want to make sure that the headers are larger than the exhaust ports on the head and that the gasket can seal well. That leads us to the intake and the exhaust valves. Once again, the larger the valves, the more air and fuel and exhaust can be flowed. These heads are matched for 1.94 intake and 1.54 exhaust valve diameters. Exhaust valves are smaller than intake valves, so don't take that as a negative sign. The intake valves are larger because of the way the engine works. It creates a vacuum to pull the air and fuel in, which isn't as efficient as pushing the exhaust out. So, the intake valves need to be bigger to compensate for that. Technical things aside, these are aluminum heads. Aluminum heads are light weight. These are 22 pounds each. That's 25 pounds lighter than the original cast iron GT 40 head, which will make for a total weight savings of 50 pounds. The other thing about these heads is that they're fully assembled. They come with the intake valves, exhaust valves, and valve springs. The valve springs are compatible with all Ford performance roller cam shafts too. Just so you guys know, when you're picking out your other build parts. When it comes to spark plugs and rocker arms, there are specific product numbers listed on the product page, but you can run with the 1.6 ratio or a 1.7 bolt down rocker arm with these heads. When it comes to price, these heads are sold individually and you're looking at $600 per head. The 64 CC chamber option costs the same, and the Ford performance heads are less expensive than the Ettlebrock options that are on the site. As far as the install, this is a difficult install and it's a three out of three wrenches in the difficulty meter. This isn't a job for someone that doesn't have much experience under the hood, and you're going to need your toolbox to get the install completed. Looking at breaking down the top end to get the install completed, so about a days work and unless you're experienced in this art and you can break a top bend down in a short amount of time. You're looking at breaking down the intake manifold, so you can completely pull it from the car. The valve covers, you'll have to pull the distributor to pull the lower manifold, all the front end accessories that bolt to the heads. You got to pull the rockers and push rods from the heads and finally drop the header so you can unbolt the heads and pull them free from the block. Once you're down to the short block, you have to clean up the block before installing your new head. So, remove the gaskets and get the block clean. After that, you can install your new heads, reinstall the lifters, push rods, and rocker arms if you didn't pick up a new set and reinstall all other parts that you broke down to pull the heads. Wrapping things up here with the Ford performance turbo swirl GT40x heads. These are aluminum heads with 58 CC combustion chambers. They come fully assembled. They offer improved air flow. They're lightweight and you can check them out more online right here at

    Product Information

    Features, Description, Q&A, Specs & Installation


    • Bolt on 65 More Horsepower
    • Improved Air Flow Over Original GT-40 Heads
    • Combustion Chamber Volume 58cc
    • Intake Port Volume 178cc, Exhaust Port Volume 62cc
    • Lightweight Aluminum
    • Fully Assembled
    • Fits 1982-1985, 1987-1995 Windsor-Style 5.0L V8s
    • Sold Individually


    More Power. Increase the horsepower and torque output of your push rod 5.0L engine with the Ford Racing Turbo-Swirl GT40X Aluminum Head. These GT-40X heads feature a 58CC Combustion Chamber to greatly improve the airflow over the original GT-40 design allowing you to bolt on 65 more horsepower.

    Improved Air Flow. These Ford Racing GT-40X heads have an intake port volume of 178cc allowing for an intake flow of approximately 240 cfm at .550" lift (at 28" of H20) and an exhaust port volume of 62cc allowing for an exhaust flow of approximately 170 cfm at .500" lift (at 28" of H20). Machined for 1.94" Intake and 1.54" exhaust valve diameters.

    Lightweight. Made from high quality original equipment style 356-T6 aluminum castings, each head weighs in at only 22 lbs. that is 25 lbs. lighter than the original cast iron GT-40 head, that is a weight savings of 50 lbs.

    Fully Assembled. Leak tested prior to assembly, each Ford Racing Turbo-Swirl GT40X Aluminum Head comes fully assembled with M-6507-J302 intake valves, M-6505-G302 exhaust valves, and M-6513-A50 valve springs. As an added bonus the valve springs are compatible with all Ford Racing roller camshafts.

    Installation Notes. Ford racing "X" heads are designed to use either GT-40 or aftermarket performance intake manifolds, M9439A50 intake gasket, and AGSF-32C spark plugs. Designed for bolt-down rocker arms part number M-6564-B351 for a 1.6 ratio or use part number M-6564-A50 for a 1.7 ratio.

    Application. The Ford Racing Turbo-Swirl GT40X Aluminum Head is designed to be a direct bolt-on for the 1982-1985 and 1987-1995 5.0L Windsor-style V8 engines. It will not fit 1986 5.0L with flat-top pistons unless pistons are notched for valve relief.

    Technical Note. Be sure to check your intake manifold for port match, because not all intakes are compatible due to the tall high-flow ports.

    CA Residents: WARNING: Cancer and Reproductive Harm -

    Installation & What's in the Box

    Installation Info

    What's in the Box

    • (1) Assembled cylinder head

    Tech Specs

    Questions & Answers

    10 More Questions

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