Unhappy with how your Fox Body performs? Maybe you’re looking at picking up a Fox Body and what to know what you should do to it? We’ve had a couple of Fox Body Mustangs, and we know how difficult it can be to decide on your first mods. After a lot of thought and research, we came up with a list of the best modifications you can to do a Fox Body. All of the modifications listed below were either installed on one of our Fox Body Mustangs, or we helped install them on a friend’s Fox.
|Type||Bang-For-Buck||Install Difficulty||Price Check|
|Intake Manifold||Good||Medium||Check Latest Price|
|Cylinder Heads||Great||Hard||Check Latest Price|
|Camshaft||Great||Hard||Check Latest Price|
|Coilovers||Good||Easy||Check Latest Price|
|Exhaust||Good||Easy||Check Latest Price|
|Chassis Stiffening||Excellent||Medium||Check Latest Price|
1. Intake Manifold
We can tell you from experience, a “cold air intake” isn’t going to gain you any power without modifying the rest of your 5.0’s intake system. Many enthusiasts don’t realize how effective the stock airbox is at drawing in cold air. Since an internal combustion engine is essentially an air pump, allowing more air into the system will result in more horsepower. The stock intake manifold on a Fox Body is relatively restrictive, especially at high RPMs. An upper and lower intake manifold will yield very impressive gains, especially at the top end of the RPMs.
A common intake is the Cobra intake manifold, but these are getting hard to find and don’t perform quite as well as modernly designed intakes. Another very popular option is the “GT40” intake manifold from the Ford Explorer. The Explorer intake is essentially identical to the GT40 intake, but again, it doesn’t perform as well as a proper aftermarket manifold. We prefer Trick Flow, their intake manifolds seems to yield the best power overall. An intake with shorter runners will result in more top end power but will rob low-end power. To see the greatest gains from any aftermarket intake manifold you’ll need an aftermarket camshaft and/or aftermarket heads.
2. Cylinder Heads
The key to making more power with any engine is in the heads. The stock E7 heads on the 5.0 flow air very poorly, and are made of heavy cast-iron. Swapping your heads might seem like a daunting task, but it’s actually pretty easy and will transform your Fox Body. Much like the intake manifold, the most common swap is Cobra (GT-40) heads. The GT40 heads flow better than stock, but are still made of heavy cast-iron. If you’re on a budget, the Ford Racing GT40-X heads are a great choice but they are far from the best.
An aftermarket head is most definitely the way to go, with modern technology companies like Edelbrock are able to blow the factory Fox Body heads out of the water. Edelbrock E-Street heads are made of lightweight aluminum and flow better than stock, we love these heads because they’re pretty cheap. If you’re going for a high horsepower build, then AFR is definitely the way to go. They make the best heads in the whole industry, but their products are also fairly expensive. TrickFlow and Edelbrock make some of the best bang-for-buck cylinder heads out there and are perfect for most street built Fox Body Mustangs.
The cherry on the cake is an aftermarket camshaft. The intake manifold and the heads perform best when complemented with a new camshaft. The most popular 5.0 cam is the Ford Racing E303 cam, providing excellent low-end torque, decent top end power, and an incredible sound at idle. When choosing a camshaft you must take into account your cylinder head flow and your desired power curve. For this reason, having a camshaft custom made for your specific set up will always yield the best results but are more expensive than off-the-shelf camshafts like the E303.
The E303 is a street cam and won’t provide maximum power at the track. Other popular cams include Ford Racing B303, F303, and Anderson N41. we should mention that if you are really serious about your Fox Body, then stay away from the 303 camshafts. Ford designed the 303 cams 20+ years ago and they don’t have the best quality control. The 303 cams also won’t make as much power as a modern design camshaft. You can read more about this in our 303 Cams article.
We should mention that the first three modifications (heads, camshaft, and intake manifold) should be done at the same time since all three of them heavily compliment each other. Seriously, just save up and do all three mods at the same time. We had an E303 camshaft, Edelbrock E-Series heads, and an Edelbrock intake manifold on one of our Fox Body Mustangs, and that set up was great for street driving; tons of torque and lots of power up high. We never had it on a dyno, but we would guess it made around 300whp. Not bad for a 2,900 lb street car!
Unfortunately, the Fox Body chassis doesn’t handle very well in stock form. Plus stock Fox Body suspension sits way to high. Most Fox Body owners swap the front suspension to coilover and put lowering springs in the rear. This generally makes the Fox chassis much more balanced, helping eliminate most of the understeer and the tail happy rear end. Depending on what kind of driving you do (street, track, canyon runs, AutoCross, etc), your desired suspension set up will vary. If you plan on making your Fox Body Mustang a cornering machine, then swapping the live rear axle for an independent rear suspension is always a good idea
Eibach makes a nice set of coil overs that are very budget friendly, and really help your Fox Body handle less like a boat. An aftermarket K-member is also an excellent modification. It essentially changed your suspension geometry to a much more desirable setup. If you plan on going to a coilover setup we would strongly recommend also getting a tubular k-member. Not only will it improve your suspension geometry, it will also save you a ton of weight, and improve chassis rigidity a ton.
As much as we would love to feature more parts to improve handling we have to mention the exhaust. Flowmaster has been making exhausts for the Fox Body for decades and they have perfected that classic Mustang sound that we all love. Of course, there are other options such as Kooks or Magnaflow, but for whatever reason Flowmasters sounds the best on Fox Body Mustangs. We had a set of shorty headers (can’t remember the brand) paired with a Flowmaster exhaust system that dumped right before the rear axle on our first Fox Body and it sounded absolutely awesome.
If you really want to go crazy you can also grab a set of long tube headers. Short tube headers are also a decent improvement over the stock headers and are cheaper than long tube headers. The stock headers are also fairly heavy and getting rid of them will help shed some weight off of your Fox. Headers will really wake up your Fox Body since the stock ones are pretty restrictive. If you’re on a budget we would definitely recommend the Flowmaster American Thunder cat back.
Of course, there are a few modifications we really wanted to mention but didn’t fit into the list of five modifications. If you really want to get serious about your Fox Body, you need to stiffen the chassis. The weak Fox Body chassis can make proper suspension setups very hard to obtain. Subframe connectors are a popular modification that really helps the chassis, as well as the ever-popular strut tower brace. Do not cheap out of these parts. Cheap chassis parts will not help your chassis whatsoever and will be a waste of time/money.
A roll cage is also a good idea. Let’s be honest, you’re reading this article because you want your Fox Body to go faster. Nobody is a perfect driver, even professionals crash. If you crash whilst racing without a roll cage you may be rolling the dice on your life. Even a simple bolt in half cage may save you and your occupant’s lives, plus it’s great for chassis stiffness. Many racing organizations won’t even let you on a track or drag strip without a roll cage.
Whether you own a Fox Body, or you are looking to buy one, we would definitely recommend doing these modifications. The head/cam/intake can gain you 100+ hp. The suspension and chassis modifications will add to the handling performance while giving it a mean, aggressive stance.