Unhappy with how your Fox Body performs? Maybe you’re looking at picking up a Fox Body Mustang 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.
3. Camshaft
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!
4. Coilovers
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.
5. Exhaust
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.
6. Chassis:
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.
Conclusion
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.
I own a 92 foxbody and love it. I’ve had others and now also own a new 2015 mustang Gt. While I love the modern ride and amazing smooth power of my new one, I still get excited to drive my fox. I really enjoy the raw feeling of it.
You missed the absolute must do’s, subframe connectors and a strut tower brace before any engine mods. Also, the stock brakes are poor. The best thing that I ever did on my old Fox that was featured in Modified Mustangs Magazine was putting on a long gone Ford Racing M2300K brake/five lug conversion kit that has 13″/11.65″ rotors F/R.
There is no reason to have a fast car if it cannot stop and the chassis flexes…
I have owned my fox for over 20 years. Wanna nice and cheap fox that goes good? Get a LX notch 5 spd w/no power. Buy sub’s, gears, K&N and remove silencer, shifter, tires, bump timing, off road h pipe and mufflers. I also recommend rear disc brakes, strut tower brace, lowering springs, and throttle body. Easy and cheap mods that will give you a fun 5.0 to drive. Thinking about buying one? Check the strut towers and the frame rails. Especially drivers side. They rust and rot out. Not a easy fix.
#5- 5 lug conversion? No way- headers and flowmasters. C’mon, it’s mandatory.
I’ve got a supposed 89 Cobra connv. Body no motor and complete 91 LX conv.
I miss my 92 everyday. Ran the Vin and it was a true cobra. Vortex v-1. Aggressive street cam. Equal length shorty headers to x pipes to Flowmaster 40 series to dumps right under your ass. Hung a little ricer muffler (not a fart can!) On the ass to confuse the losers eating my dust. Air shocks in front, quad shocks in back, mini tub, MEAT micky Thompson e/t street radials, plans for rear and axles and 5 lug, back to “done colum”…strut tower brace sub frame connectors, tremec tko that never got installed because the little rascal t5 that required double clutching to and from 3rd and 4th just wouldn’t grenade… that held up a time slip, and sadly even a dyno pull…. truly sad. Cervinis 4” cowl hood, smoked stock tailights, cobra-r chrome wheels with their 5 lug brethren hanging on my bedroom wall waiting for their time to shine…. pearl white house of Kolor (?) Finish. Short throw shifter , under drive pulleys, ac delete, emission bullshit delete, egr delete, heater core delete (never felt like fixing it) perelli rubber , big cross drilled and slotted rotors up front to make up for adjusted very loosley for that low resistance brake stand that would make anyone proud. 5his car was a monster. Shat on cars like 1000% the price tag, shat on then 4cyl jap bikes that were no slouch… this thing was a monster and I miss it every day…. a friend of mine did the head work on what I believe was an aluminum copy of the gt-40s…. we’re there when I bought it from the nephew of a mechanic co-wo4ker. Interior gut. Cage that I “learned” to weld making. I wouldn’t embarrass myself nhra inspecting it but it did suprise everyone at SCCA auto cross events. Msd ignition kept in the glovebox, k and n filter for that guaranteed 10% lol. Gutted upper and lower cobra intake manifold. Everything ported and polished like a burr or the weight of a grain of sand would crash the project. Plumbed for nitrous but I would never hurt my baby. Brown top injectors (I do believe I recall) controlled by a top secret EMS , conducted by a top secret cam grind. Oil pan that was couple hundred dollars overpriced. Windage eliminating doohickeys with automatic headlight fluid heater. Air to air intercooler. Trans cooler, oil cooler, all crammed in there looking like a 7.3L. Basically gave the car away for a steal cuz sometimes life puts it’s boot on the back of your hear. If your reading this and you got my car at deal of a lifetime luck. Bring her on by I’d like to see how you could imagine improving it or doing another infinity-foot burnout or a bakers dozen of doughnuts. I’ve ow3d every year car from 79 to 96. And this was the only one I really loved. Never defeated on the street, with shot sincros and a driver who could smoke Willie Nelson out of house and home.
What a novel…. that’s how truly loved and pushed to the limits of a shock block with a girdle you can go. Pushed over half an atmosphere with 130+ thousand
I am 66 years old and just retired. I have always been a ‘car guy’ and a big Mustang fan, but have never owned one. I told my wife that I may be the first mustang fan to go to his grave having never owned a Mustang. WELL… while on my retirement vacation and 6 states away from home I came across ‘the deal’. A 1984 Mustang LX convertible, one owner (deceased), always garaged, covered and babied. There is not a speck of rust, spotless interior, all stock, even the original paperwork, and (get this) 28,480 verifiable miles (odometer, service records per CarFax). All out, including a tank of gas, just under $4,000. It drives like a dream too. The Foxbody was my least favorite body… until now. Now I am in LOVE with the Foxy Mustang. I am going to cruise around Seattle for another month and then decide how best to ship it back to Texas.
If your a young kid looking to get into the fox life, let me simplify this in that what the REAL first 5 mods should be, without a doubt. Bryce is knowledgeable on these cars for his age, but he s coming from the wrong angle with his advice, if your a true newbie, probably younger with limited funds…these assumptions I will take for else you wouldnt be reading this article.
1. sub frame rails. don’t waste time with bolt on ones. Have a Pro weld these in so to be sure straight,strong, foundation. The torque Bryce mentions will totally twist and ruin car without these,… so all used ones without one all these years???? you gotta check torque boxes, shop can help to straighten out it it’s not too bad.
2.Aftermarket shifter/complete with adjustable stops. Stay away from just the shorter handle, defeats the purpose. Hurst & Pro 5.0 are two of many to consider, this can save your T5 s forks and whole transmission for this matter. It will allow for easier(spring mechanism for easier 2nd to 3rd) shifts and harder for the adjustable stops prevent slamming for shift into and damaging forks.
3. Cold air kit – There are 50+ to choose from. Do your own research for there is pro s and cons to each design. some like to locate the filter into the fenderwell, you may think this optimal but the bend in the tubing/airflow and be troublesome to some types of aftermarket, even factory air meters. if you get an conical style, make sure to have some type of shield to prevent fanwash and underhood engine heat from entering t your filter. Generally I think the stock airbox with K&N filter along with air silencer removal is optimal for beginner.
3a. After helping with a little more air in, you wanna help it get out so your exhaust should go along with this mod in my recommendation s here, off road pipe with cat back(tailpipes and mufflers)…
4. Gears -3:55 or 3:73
5. Underdrive pullies are best band for buck. 10-12 up for $80.
Sidenotes:: your H/C/I swap should be done at once, hence will be costly, this is ultimate goal but not something to consider until these mods above are done, which also involve more supporting equipment for them to work optimally, throttle body, mss air meter, injectors, headers, etc. (do not waste money on headers if your motor is stock).