Ford began producing the Fox Body Mustang in 1979. Production to would run from 1979 to 1993 with an aesthetic upgrade inside and out in 1987. Over 2.6 million Fox Body Mustangs were built over fourteen years as hatchbacks, notchbacks, and convertibles, with a range of four, six, and eight cylinder engines. It is a mechanically simple, lightweight car with a massive following. The name comes from it sharing Ford's Fox chassis platform with many other cars. The premiere V-8 Fox model came with the legendary small block Windsor 302 cubic inch 5.0 liter engine.

The Fox Body Mustang is not excellent at anything, its 5.0 V-8 engine produces only 225 horsepower, the weight distribution favors the front, the brakes are easily overpowered, the chassis is flimsy, and the suspension is lacking. Popularity is the Fox's saving grace. If it was unpopular, it would be a rightly forgotten car. It is easy to see why the Fox Body is so popular: it has an attractive angular design and it is easy to modify – it is the epitome of a tuner car and can be built into a seriously wild ride. What follows are the most popular Fox Body Mustang modifications.

Related: 5 Reasons Why The Fox Body Mustang Was The Best 80s Muscle Car (5 Reasons Why We'd Rather Have A Buick GNX)

10 Intake Manifolds

Stock longrunner Via Foxstang.com
Via: Foxstang.com

The factory fuel injected 5.0 High Output intake manifold is unattractive and performs poorly. Thankfully, the Longrunner intake is easily replaced. Because of the Fox Body's popularity, there are an unfathomable many aftermarket and Ford-produced intake manifold replacements like Ford's GT-40 intakes, Cobra intake, Holley Systemax II, the new Holley Hi-Rams, and the list of Edelbrock and Trick Flow intakes.

Longrunner intakes Via Corral.net
Via: Corral.net

Replacing the factory intake increases the under-the-hood aesthetics of the Fox Body and the engine's performance. A 5.0 H.O. engine can see some healthy gains when a quality intake is combined with a properly sized throttle body, EGR spacer, cold air induction, and a some more degrees of timing. These modifications are easy to perform with few tools in a timely manner and at a low cost. Plus, a well sorted 5.0 with these mods can see about 20+ RWHP on pump gas.

9 Camshafts

Fox Body Via FordMuscle
Via: FordMuscle

When Ford was building the 1993 Mustang SVT Cobra, the engineers decided to change a few things for the engine. The most obvious change was the intake manifold. Two other changes happened, though. Ford engineers also changed the heads and the camshaft. Having better flowing heads on an engine is a good thing because better flow leads to more power and torque. Better flowing heads alone, though, are not enough. A properly sized camshaft for the heads and use of the car is also required.

fox body 2 via SVTPerformance
Via: SVTPerformance

Since the 5.0. H.O. engine is a pushrod, over-head valve engine, changing the cam is a time consuming process – but necessary. Ford used a camshaft in the Cobra that is slightly larger than standard that made decent use of the new GT-40 heads. However, no factory camshafts for the 5.0 were excellent. Even Ford recognized the need to change the cam and produced the famous 303 camshaft series. Today, practically every major valvetrain company and professional small block Ford engine builder has a hefty list of camshaft options for the 5.0. Of course, if you are not so fortunate to own a '93 Cobra with factory engine mods, then, by swapping your intake and cam you can pick up some nice horsepower numbers, even with stock E7TE heads.

8 Heads

HEADS Via Forgeline Wheels
Via: Forgeline Wheels

Since you have to remove the top half of the engine to change the cam, it makes practical sense to swap the factory E7TE heads to better-performing cast or aluminum heads. There are ample cylinder head options for the 5.0. The factory heads are okay at best for street bound engines with a small cam, intake, and a power-adder. However, so much performance potential is left on the table with the stock heads. When the heads, cam, intake, and tune work well together, one can potentially see approximately mid 300's for horsepower at the rear wheels – a healthy output.

cylinder heads 1 Via OnAllCylinders
Via: OnAllCylinders

There are cylinder heads available for the 5.0 engine at virtually every price point. The 5.0 saw service in many Ford vehicles and it shares many design features with other small block Ford engines. Ford cylinder head options began with the cast iron and aluminum GT-40 series and grew into the Z series of heads. Companies like Trick Flow and Air Flow Research (AFR) are leaders in small block Ford aluminum head options. Trickflow, Edelbrock, and Dart produce top-end kits that include a cam, heads, gaskets and hardware, and often an intake because of how popular it is to change all of those components together.

7 Clutch, Shifters, Or Shift Kits

Fox Shifter Via Holley
Via: Holley

Once a hefty 5.0 is built, the stock clutch will not last for very long. With 300, or more, wheel horsepower in a light car, it is difficult to forego burnouts, clutch dumps and kicks, and power shifting to enjoy your fast Fox Body. A necessary modification to make is a clutch upgrade in for a manual T-5 or a shift kit in an AOD transmission. The T-5 transmission came stock in manual equipped Fox Bodies. A T-5 with a good clutch and occasional spiritied driving might last a while behind a 500 horsepower 5.0. However, the T-5 itself is only rated for about 330 foot-pounds of torque, so a quality clutch is essential. As for the shifter, Hurst and Steeda make popular and attractive options that perform well in reducing shift time for the manual.

%22clutch%22 Via Mustang Specs
Via: Mustang Specs

Ford's four-speed automatic with over-drive (AOD) transmission with a little work can be a fun transmission capable of supporting about 450 horsepower. Either the T-5 with a quality clutch or a lightly built AOD is a solid option for a spiritedly-driven street-duty Fox Body. Yet, if you want your Fox's driveline to be reliably capable of hard lauches off the line at the drag strip, or you want your corner carver to handle rowing the gears, then the aftermarket is there to help. Companies like TCI and Monster transmissions produce a range a quality automatics. Virtually any Tremec manual tranmission can be swapped into the Fox chassis with the right bell housing and cross-member.

6 Supercharger/Turbochargers

Vortech Via Lethal Performance
Via: Lethal Performance

One has to be careful when using a supercharger or turbocharger on a 5.0 engine. While the engine responds well to heads, cams, intakes, and tunes, a power adder mixed with modern tuning capabilities can be disastrous. A well built 5.0 with a power adder can make healthy horsepower numbers quickly. A poor tune and too much torque can split the factory engine block down the middle from the lifter valley to the crankshaft main caps. The OEM 5.0 engine block is a delicate thing. However, with a quality tune, forged rotating assembly, main cap girdle, and some moderation, the stock 5.0 block can hold plenty of power.

Via SVTperformance.com
Via: SVTPerformance.com

If you really, really want to make some big power, there are quality aftermarket engine block options from Dart, Ford Racing, and World Products (or you can swap in a 351). A block swap is a good idea for those of us who cannot resist the boost sounds and easy horsepower offered from turbos and superchargers. The centrifugal superchargers are wildly popular for the Fox Body; the location of the distributor makes a twin-screw or roots style supercharger difficult to use. A first generation Vortech S-Trim has that characteristic centrifugal whistle. However, newer generations of Vortech 'chargers and companies like Paxton, Novi, and Procharger are other excellent and kind-of quieter options. Turbos: On3Performance makes the most popular and cost effective turbo kit for the Fox that has all of the necessary components for turbo bangs and blow-off valve noises.

Related: Here's Everything You Need To Know About The Centrifugal Supercharger

5 Final Drive Gears And Rear End Upgrades

Gears via FordMuscle
Via: FordMuscle

Muscle car gearheads know full well the fun of rear end gear changes: high gears equal easy burnouts. Final drive gears consist of pinion and ring gear. The relationship between the number of teeth on each gear determines the final drive ratio which has the most obvious impact on acceleration and top speed for any car. Popular final drive options for the Fox Body are ratios 3.73 and 4.10. The car responds well to those gears with either an automatic or manual and with a stock engine. However, a modded Fox requires a final drive upgrade for maximum or tailored performance.

gears 5 Via @DTM Twitter
Via: @DTM Twitter

Many Fox Body Mustangs came from the factory with Ford's 8.8'' solid axle rear end. Some came with the smaller and less popular 7.5" rear end, like the SVO and early Foxes. Regardless, your Fox likely has an 8.8" rear end. The 8.8" is a strong and modifiable rear end. There are numerous upgrade options that are specific to the 8.8" in the Fox. Moser makes excellent axles, Eaton, Auburn, and Detroit Locker make wonderful 2-way differentials and solid spools. Ford Racing provides quality final drive gears in numerous ratios, so one does not need to look hard to find the perfect pair. You can build the 8.8" for any kind of racing you desire.

4 Chassis Stiffening

twisting Via Fuel Curve
Via: Fuel Curve

The Fox Body is built on Ford's Fox uni-body chassis platform, meaning there are many Ford cars built at the same time that are also "Fox Body" cars. Unfortunately, the Fox platform does not have much torsional rigidity: it twists easily. There are numerous ways to stiffen the Fox chassis, fortunately. A street driven Fox Mustang with a hearty 5.0 is safe with subframe connectors. Subframe connectors attach the front of the uni-body to the rear of the uni-body across the length of the undercarriage beginning near the firewall and ending before the rear wheel at the torque boxes.

twisting 2 Via Pinterest
Via: Pinterest

What twists a car? Torque and hard cornering are the biggest causes of chassis twisting. Since torque is delivered to the rear end, the the Fox is rear wheel drive, and the engine is bolted to chassis at the front, it is easy for the engine outputs to twist the front of the car and the back of the car differently: engines move when under hard throttling, so a powerful engine will move a lot and will move a weak car a lot all over. Subframe connectors increase the torsianl rigidity of the fox by further unifying the chassis. Yet, subframe connectors may not be enough. Weld-in roll cages and torque box reinforcements aid considerably to the Fox's torsinal rigidity. The torque boxes are made a thin sheet metal and attach the rear end to the car via the lower control arms. Reinforcing the torque boxes helps keep the weakest of the back end of the car sturdy.

3 Dampers And Springs

Dampers 1 Via Safety Stance
Via: Safety Stance

From the factory the Fox Body Mustang does not handle well. It has a front weight bias that contributes to understeer. With a solid rear axle, unless the back tires are wide and grippy, even a mild Fox will have a lively back end. There is no shortage of tire spin with the Fox Body Mustang. Pretty much everyone, even Ford, knew that about the Fox. So, companies like Saleen and Kenny Brown focused on upgrading the Fox with shocks, struts, and springs.

Group A Via Artebellum
Via: Artebellum

These modifications are popular in the aftermarket as well. Eibach and Steeda have produced damper and spring kits, occasionally with sway bars that are perfect for spirited street driving. Making the car lower also helps it look much nicer. However, not all companies or products are created equal. Maximum Motorsports, for instance, the leader in Fox Body handling upgrades, pieces together kits that range from simple shocks and strut packages to all out racing packages that include subframe connectors, panhard bars, sway bars, and coilovers. Though, unless you are time attack or autocross racing your Fox, Bilstein Shocks with Steeda lowering springs make a night and day difference to the Mustang's handling – especially with a stiffer chassis.

2 5 Lug Swap

4 lug Via Northern California Ford Owners
Via: Northern California Ford Owners

From the factory the Fox Body Mustang came with a 4 lug bolt pattern. There are not any compelling reasons for why Ford chose only four lugs, previous generation Mustangs came with five. Having four lugs is not a major set back because there are some performance brakes, axles, and rim options. However, it makes financial and practical sense to change from 4 lugs to 5 because then one has access to way more performance products.

IMG_1731

There are a few ways to perform the 5 lug swap. One could simply change the front rotors, replace the rear axles and brakes, and leave everything else stock. Doing this retains the factory front calipers and maintains rear drum brakes. Another popular option is to swap SN95 Mustang front spindles, ideally those from a 1994-1995 Mustang. Then, the range of SN95 brakes are available for the front. A most common sight is SN95 Cobra 13'' rotors and two piston Cobra calipers. It is not technically necessary to change the rear to disc brakes and 5 lugs, but it is nice.

Related: Here's How The Ford Fox Body Mustang Generation Compares To The Others

1 4 Wheel Disc Brakes

Discs Via Mecum
Via: Mecum

Nothing brings the Fox Body Mustang up to date like having four wheel disc brakes. If built well, the Fox Mustang can be wildly fast, an excellent car for spirited driving, and a great track car. Drum brakes and small disc brakes are quickly overpowered, either because a car is simply too fast for it's brakes, or the car is being driven too hard – both are precisely what can happen with factory Fox brakes. Upgrading to four wheel discs is thankfully easy to do on a Fox Mustang.

Inner race car Via Fuel Curve
Via: Fuel Curve

One could simply swap practically everything, five lugs and all with little modification, from a newer SN95 Mustang into the Fox Body. Ford understood how antiquated the Fox's braking system is when they produced the 1993 Cobra R. 1987-1993 V-8 Mustangs came with 11'' front brake rotors and single piston brake calipers. The Cobra R saw 13'' front brakes, SN95 Cobra two pistion calipers, and rear disc brakes. However, there are numerous aftermarket suppliers like Baer and Wilwood that make excellent disc brake kits. It is important to remember that you can build a car is impressively fast, but it is more important that the stopping power matches the acceleration.