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Throttle Position Sensor Adjustment (Green and Black Wires)
To maintain optimum performance of your 5.0 L check the setting of the throttle position (located on the top of the throttle body). Accurate adjustment will provide smooth idle and good acceleration. Using a digital volt meter or a multi-meter with the ignition key in the "on" position; but with the engine off, voltage should read between .997-999; 1.1 to 1.25 for supercharged cars. Adjust (elongate the slots if necessary) the sensor to obtain proper setting by loosening the mounting screws and moving the sensor side to side.

Ignition Timing
Most 5.0 Mustangs are delivered from the factory with the ignition timing set from 4-6° BTDC (Before Top Dead Center). Stock is 10°. With premium fuel, start at 13°-14°. If you have no detonation, increase upward. Timing is free horsepower and will run better up to 19°-21° of timing.

Camshaft Installation
When installing a flat tappet cam (non-roller) it is important to install new tappets or lifters, valve springs and retainers. When installing a roller cam, '85 and up H.O. blocks, you don't have to change the lifters until 40,000 miles unless the lifters show wear. Also, if your motor has high mileage or if you are changing to a cam with very high lift, change your valve springs.

  • Always use the right type of lifters or tappets with your cam.
  • Always match your parts. One of the biggest mistakes is the installation of a cam that is too big (too much lift and duration).
  • Flat tappets cams must use prelube before installation. Roller cams are made from steel billet and only require a generous coating of fresh engine oil.
Transmission Maintenance
We suggest changing the fluid in a T-5 transmission at least every 10,000 miles, more often if the car is driven hard. It requires less than 3 quarts of Mercer-Dextron automotive transmission
fluid - nothing else can be used. You can use synthetic Mercer-Dextron.

Cylinder Head Torque
When tightening head bolts, torque the upper bolts (near the intake manifold) to 80 ft-lbs and the lower bolts near the exhaust manifolds to 72 ft-lbs. When you tighten the intake manifold, this tends to generate a lot of upward pressure on the heads. The additional tightening of the upper bolts compensates for the upward pressure. Be sure to coat head bolts or studs with non-synthetic oil before installation.

Roller Rockers
The selection of rocker arms will be dictated by the type of camshaft and heads. Any 5.0 worth its weight should use roller rockers. Stock rockers are adequate at best. They are designed as 1.60 but seldom are. Stock rockers vary in ratio from 1.45 to 1.66 and flex too much. When installing roller
rockers, be sure to remove the valve cover baffle on the right hand side of the valve cover. And shim the rocker arms if necessary.

Silencer Removal
One of the easiest modifications you can make on an '86-93 5.0 Mustang is to remove the air
cleaner silencer as soon as you get it. The air silencer is located behind the right hand side fender. Removal allows increased air flow to the engine. Also, install a K&N air filter as it will be the last filter you buy and will increase performance.

Keeping Cool
A cooler engine produces more power. The stock 5.0 Mustang thermostat is rated at 192° which is fine for most. Installing a 180° thermostat will cause the engine to run slightly richer thus
producing more power. Don't install a thermostat cooler than 180° or remove it altogether.
This will prevent the engine from reaching proper operating temperature and performance will suffer.

Adjustable Fuel Pressure Regulators
Fuel starvation with modified 5.0 Mustangs is a common problem. By installing an adjustable fuel pressure regulator you'll be able to increase pressure from the 38-39 lbs factory setting up to 55 lbs (if needed).

Fuel System
One of the most commonly overlooked upgrades is the fuel pump. When changing intakes, heads or injectors, depending on modifications, the pump will need to be changed to a 110 lph or 155 lph. If you use a supercharger or nitrous, a 155 lph pump minimum will be required. Depending on boost levels or nitrous levels, a 190 lph pump may be required. When upgrading the pump, it's recommended to change the regulator to an adjustable type with a gauge so exact fuel pressure can be set and monitored.

Exhaust Improvements
One of the most restrictive elements of a stock 5.0 Mustang is the factory exhaust system. With all the dimples and bends in the factory headers and pipes, unnecessary back pressure is created in the exhaust system. Installing headers and a performance exhaust system will not only make your Mustang sound better but the performance gains are quite noticeable.

When supercharging your mustang, it is necessary to upgrade your ignition system. With the high boost levels, a stock coil cannot keep up with the requirements to properly fire the increased
mixture. A MSD multiple spark box will be required along with a high performance coil (like a Motorsport or MSD). If you have a lot of modifications (cam, heads, intake, injectors, and NOS or a supercharger) the addition of the Motorsport RPM extender can increase the power output
dramatically by increasing air/fuel ratio and RPM limit.



Dieting Time
Mustangs are very weight conscious! Removing any unnecessary weight will only help
performance. Hint: Try removing the insulation under the carpeting in the hatch area on hatchback models. This is usually about 15-20 lbs.

Strut Removal
When removing stock McPherson struts make sure you have the proper "slotted socket" to hold the upper shaft in position. It's available through Craftsman and other leading tool manufacturers.

Front Suspension Alignment
Most Mustangs are delivered from the factory with the camber set at 0° or slightly negative. Ideal setting is -3/4° to -1° for aggressive street driving. This will reduce the "feathering" effect commonly seen on the outside edge of the tires while improving handling through corners.

Lowered Mustangs
Many Mustang owners like to lower their Mustang for improved handling and appearance. As with anything, there is a right way and a wrong way. Cutting the stock springs will certainly lower the car but handling will suffer. We suggest installing aftermarket springs made specifically for this purpose. Several varieties are available and directly replace the stock springs. Lowering a Mustang more than 1 1/2" lower than stock is not recommended without major suspension modifications. The stock suspension geometry is not designed to operate at that level.

Chassis Stiffening
If you drive your Mustang on a regular basis, consider installing subframe connectors. Not only will they stiffen the chassis (reducing body flex), but our subframe connectors support the floor pan at the seat mounting area which has been know to stretch and tear over time. Our strut tower brace and lower chassis will reduce flex and stiffen the front suspension (keeping the front end tighter during cornering). (top)


Hurst Shifters
Installing a Hurst shifter is the best preventive maintenance you can perform on a T-5 transmission. The adjustable positive stops prevent over-shifting and bending the shift forks. When installing a Hurst shifter be sure to properly adjust the positive stops. Incorrect adjustment will result in the transmission "popping" out of gear or bent shift forks. (top)


Increasing steering accuracy is easy on lowered Fox Mustangs with a simple bushing change
(Taken from June 1993 Super Ford article by Earl Davis)

What is bump steer and where does it come from? Bump steer is not the name of a new carnival ride although it could describe the way some people drive. Bump steer is the term used to describe the steering misalignment or geometric inaccuracies resulting from suspension travel. Okay, so that doesn't exactly make the concept of bump steer clarion clear in your mind. Think of it this way. Bump steer is any unwanted toeing in or out of the front wheels as the suspension is compressed or extended. It is caused by the geometry or relationship, between the steering linkage (rack, tie-rod ends) and the suspension (especially the steering knuckle, upright or whatever you want to call the piece where the tie rod end attaches to the suspension). If the steering and suspension move in different arcs (and they always do, somewhat), then the distance between the center of the steering system and the suspension will vary. That forces the wheel to toe in out as the steering alternately "lengthens" or "shortens." Then the car does not steer accurately during cornering. Lowered cars usually suffer from increased bump steer because the suspension geometry has been changed where the rack has been lowered in relation to the centerline of the spindle. To help remedy this problem we offer off-set rack bushings for '79-93 models or the 1990-93 tie-rod ends for 1979-89 models. Either solution works equally well by itself but not together. (top)


To remove the dash cluster on a 1968 Mustang, remove the bezel screws and then the speedometer cable. On some years, you may need to drop the steering column and remove the wiring.


289 V8 302 2V

(click for a larger version)

(click for a larger version)



1. Clean the area where the decals will be applied with Windex or a soft cloth dampened with denatured alcohol. This will remove any wax, oil or dust particles that will prevent the decal from sticking.

2. Carefully peel the tape and decal away from the paper backing, hold the decal in position and stick. Rub the entire area firmly from one side to the other with your fingertips or the sharp edge of a credit card. The decals have a pressure sensitive adhesive and the harder you rub the harder it sticks.

3. Remove the application tape by pulling gently in a downward position.

Note: The decals will not adhere to a surface that has been waxed. Remove all wax and residue with Windex or denatured alcohol before application. After the decals have been applied, the surface can be waxed over. The wax will not damage the decal, but will prevent it from sticking.


For large decal application, hold the decal in position and stick the top or one side in place. Then using the sharp edge of a credit card working your way from top to bottom with firm pressure to prevent any air bubbles. To apply extra large decals we recommend getting someone to hold the decal in position while the other person rubs it in place. If you are uncomfortable with the process you may consider professional installation at your local sign shop.



Click here for full instructions (with photos) on how to install a front spoiler on your Mach 1!



Most aftermarket or original emblems usually have the prongs on the back along with an adhesive backing. In most cases if your car does not have existing provisions for this you can use a razor or Dremel tool to remove these prongs and use the adhesive backing for installation.



1. Subframe connectors must be installed on a level car. The best way to achieve this is by using a car ramp (as found in an alignment shop). If this is not available use four jack stands to support vehicle. The jack stands must be level with each other when supporting the vehicle; if this is not done, severe body alignment and steering problems may result after bolting or welding the subframe connectors.

2. Once the car is supported and you are able to get under the vehicle you will either weld or bolt them in place. If you will be bolting the subframes in place you will need a right angle drill gun, 3/16” and 3/8” drill bits. If you will be welding them in place you will need a welding machine (preferably a heli-arc welder), drill gun, and 3/16” drill bit. If you will be welding, make sure you cover the fuel line with a damp cloth for safety purposes and have a fire extinguisher available.

3. Mount the driver's side connector in place with larger bracket towards the back of the vehicle. Once in place and pushed up as much as possible mark the holes for drilling or weld in place. Drill holes and slide bolts in place.

4. The passenger side requires a little more work. First you must remove the triangle bracket (1993 models and earlier) that holds the fuel line in place that's located just forward of the lower control arm mount. You will need a 10mm wrench to remove the bolt. There is also a bracket holding the fuel line about 12” farther toward the back of the vehicle which also needs to have its bolt removed. Take a screwdriver and pry the plastic plugs off the fuel line toward the front of the subframe connector. Once these are removed slide the connector up into place so that the fuel line remains above the connector after you weld or bolt it into place.

5. Once the connector is welded or bolted into place you will no longer need the triangle bracket removed in the previous step. Readjust the fuel line so that the bracket farther back on the fuel line can be moved back into its original location. Drill a 3/16” hole and relocate the fuel line bracket so that is it located near the front of the subframe.

6. You are now ready to lower the vehicle. You may want to touch up the paint around the subframe connectors on the body so that rust spots don't appear.



1. Disconnect the battery. Jack up the vehicle and support it under the suspension with jack stands;

2. Remove the bolts for one side of the midpan crossmember and sandwich the  Connector between the floor pan and midpan crossmember using the existing bolts and nuts. Hand tighten. On Driver’s side, reposition brake lines around Subframe Connector by drilling small holes to remount brake line clips;

3. Using a floor jack, raise the rear end housing to approximate ride height. Remove the rear lower control arm bolt (chassis end) slowly and only far enough so that it is still half way in the lower control arm bushing. Insert a drift pin (or bolt approximately the same diameter) to hold the lower control arm in place as you remove the original bolt. Line up the hole at the end of the  with the rear lower control arm hole and reinstall the bolt

4. Tighten the two midpan crossmember bolts and the rear lower controll arm bolt to factory specifications;

5. Weld connectors to subframe of the car.  It may be necessary to use a jack to mate the Subframe Connector flush to floor pan in some cases;

6. Weld this tab to the factory pinch weld located underneath the car;

7. Repeat these instructions on the opposite side of the vehicle.

8. After welds have cooled, we recommend that a rubberized undercoating be applied to the welded areas to help resist rust.



Axle ratio/Tire size calculator

Speedometer error calculator

VIN calculator

VIN Dataplate decoder

Tire size calculator


What you will want to do is count the teeth on your drive gear, wrap a string around your new tires to figure out the revolutions per mile. Now multiply the drive gear (x) rear gear (x) tire revolutions per mile. Divide that number by 1000 and that will give you your approx. driven gear teeth needed.


drive gear teeth = 7
rear axle ratio = 3.73
tire rev. per mile = 815

7 x 3.73 x 815 / 1000 = 21.3 (21 tooth gear needed)







Old top removal:

  1. Open two front latches.
  2. Raise top halfway.
  3. Remove front weatherstrip and staples from top.
  4. Remove front side weatherstrip and quarter window weatherstrip.
  5. Pull away glue on quarter flaps.
  6. Remove tension cable on each side.
  7. Remove screws from two bow pockets in center.
  8. Remove wire-on staples and staples from rear bow.
  9. Peel back top, remove staples holding top of glass.
  10. Remove rear seat for easy access.
  11. From inside of car, remove bolts from trim stick.
  12. On inside of top, chalk mark position of top and glass on trim stick.
  13. Lay protective covering on trunk of car to prevent scratches.
  14. Lay trim stick on trunk and remove staples from glass and top. Top should now be completely removed.

New top installation:

  1. Close top to check bow height (which is 25 1/4"from center of rear bow to chrome on trunk).
  2. Lay old window on new one and mark bolt holes and staple marks.
  3. Staple window to trim stick and install with three bolts, then staple top to rear bow pulling side to side to eliminate wrinkles, then remove trim stick.
  4. Place old top on new top and mark for bolts and staples.
  5. Staple to trim strick in same position and bolt back on.
  6. Pull top forward on frame, replace cables and screw in bow pockets.
  7. Close frame with top pulled all the way forward.
  8. Chalk top to front edge of bow.
  9. Lift up top halfway and staple front 3/4" back from mark to make top tighter, stretch to each side.
  10. Glue front side of flaps and replace weatherstrip.
  11. With top closed, staple top to rear bow and staple wire on and tips making sure to cover staples.
  12. Replace rear seat.
  13. Car is now ready.


  1. The modular engines with factory forced induction like the '03 Cobra and the Lightning will benefit from improved exhaust flow.
  2. The X-Pipe with mandrel-bent 2 ½ inch tubes add 5-10 horsepower over the production pipes. The stainless construction of this pipe ensures it will last a long time.
  3. The sound of the H-Pipe is different than the X-Pipe. The H-Pipe produces a low rumble, similar to the muscle car sound of the 1960's. The X-Pipe produces a higher pitched sound, more like a european sports car.
  4. The 97-up mustang cooling fan and shroud flows well, and does a good job of cooling in traffic. '96 mustangs can be upgraded with the '97-up radiator, fan, and shroud for improved cooling.
  5. A heavy duty automatic transmission oil cooler will improve the transmission life and reduce stress on the engine as well. Transmission oil coolers are normally rated by gross vehicle weight(GVW) so the higher the value the more capacity the cooler has.
  6. The vortec S-trim supercharger was the first widely distributed centrifugal supercharger for the 4.6.
  7. The Vortec aftercooler is an air-to-water heat exchanger that will drop the discharge temperature of the supercharger air, increasing efficiency. The aftercooler is best suited to drag racing at 10 PSI or below.
  8. Procharger P-1SC is ATI's entry level street supercharger. Their blowers are unique in that they carry their own oil supply, rather than using the engines oil system to supply the supercharger's requirements.
  9. When using 99-up PI heads on your 96-98 mustang, you must also use the matching 99-up Motorsport intake manifold.
  10. The 5.4 liter windsor iron block is similar to the 4.6-liter version. The deck height is 10.079 versus the 8.937 inches on the 4.6L.
  11. The billet steel 4.6 crankshaft is manufactured from 4340 steel. The crankshafts can be ordered with various strokes and options such as knife edging and reduced journal diameters.
  12. Stock 4.6 liter engine uses a powdered-metal rod with a cracked cap. The unique surfaces created when the cap is cracked and sperated from the rod. This means that each cap must remain with the connecting rod it came from, for the life of the rod.
  13. Detonation will damage the stock piston by fracturing the ring land. The damage may go undetected for some time, since it causes no apparent noise. Eventually, oil will work past the rings into the combustion chamber, at which time the damage is usually noted.
  14. The factory has produced the 2-valve engine with the 11-cc dish from 92-98 and the 17cc dish since 1999. Resulting in a compression ratio of 9.3:1.


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