EFI 5.0 Installation - 65 Mustang Fastback
Doing an EFI swap was the single largest task I had taken on since owning my 65 Fastback.  There was actually nothing wrong with the 302 I had before, but wanted a classic that would get good gas mileage, start and run consistently and smoothly, and not make me worry about taking off on a long distance drive.The install is rather complex, but not difficult.  Complex only in the larger number of items that must be addressed beyond a normal engine removal and replacement.  I've tried to address the differences in the sections below.

There seems to be an infinite number of combinations of parts and mods when it comes to doing an "EFI Swap".  Everyone's situation is different.  After researching many of the different variations, I think I ended up with one of the simpler swaps.

  • Used a late model T-5 transmission, bellhousing, flywheel and clutch, therefore requiring no special adaptations.  The complete drive train from harmonic balancer to output yoke are stock 1990-1991 Mustang components.
  • Used a serpentine belt, which did not require any changes to the timing cover, harmonic balancer, or water pump.  Aftermarket brackets from Trick Flow (A/C Eliminator) and March (Alternator)  were used to mount the accessories. 
  • Used the stock MAS rubber intake tubing, requiring no special plumbing.
  • Used an aftermarket Aluminum Radiator with inlet and outlet on the sides matching the motor.
  • Stock EEC, sensors, and ignition system
  • Stock fuel rails, fuel pressure regulator, and fuel feed lines.
  • Stock 2G Alternator (Aftermarket mount)
  • In fact, the engine is bone stock, requiring only modifications to fit the vehicle.
Check out this 35K mile donor motor!
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Engine Preparation: 
In order for a later model 5.0 to fit in an early Mustang, either the oil pan needs to be changed or the car's cross bracing/steering must be modified.  I chose the simpler and changed the motor's lower end setup.  Note the different in Early (64-72) and Late (79-95) Oil pans.  The rear sump of the late model interferes with the cross member and steering.  Required are a replacement SBF 260-289-302 oil pan (Ebay for <$35), and a new oil pump pickup tube/screen (Melling brand pickup tube/screen is <$10 @ Autozone).  The Oil Pump Pickup photo below shows the Melling unit installed and ready for the new pan.

While you're in there, you'll need to relocate your oil dipstick from the side of the block to the front timing chain cover.  First remove the old dipstick and discard.  I used a wooden dowel to seal off the old hole.  After the pan was installed, I tapped the wooden down in the hole and left it.  The dowel absorbs hot oil and seals off the hole.

The dipstick must be relocated to the front of the motor (Dipstick Location 1 below).  This can be done on or off the motor.  Photos 2 and 3 below show where the boss exists in the cover.  A drill bit sized to the oil dipstick diameter is used to drill out the boss and the oil pan compartment.  While I had the pan off, I cleaned this corner of the pan/block with solvent, then masked it off to ensure no shavings could migrate into the lower end. (Pretty gutsy eh?) The motor bottom end was taped off completely.  After first drilling a 1/4" pilot hole, I stepped up to the correct diameter bit.  Care must be taken to ensure you establish the correct angle so the dipstick tube can extend up between the alternator and the head. Photo 4 below shows the completed dipstick installation.

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Oil Pump Pickup Dipstick Relocation 1 Dipstick Relocation 2 Dipstick Relocation 3 Dipstick Relocation 4 Early Model Oil Pan

Recommend spending the extra few dollars and buy the high quality 1 piece Felpro oil pan gasket.  This is a steel cored synthetic rubber coated unit.  You DON'T want your oil pan leaking.  When installing your new oil pan, make sure your mating surfaces are perfectly clean, and the gasket is clean.  Use the plastic ears that come with the gasket to hold it in place while installing.  Tip: SBFs tend to leak oil at the 4 corners where the tabs of the gasket slip into the slots around the fwd & aft crankshaft journals.  Use a little RTV to seal off these corners.

Motor mounts:  The two photos (right) show the two pieces of a 1966 motor mount.  The lower unit is bolted to the shock tower frame, and the upper unit is secured to the mounting holes on the side of the block.  When the motor is dropped into place, a single bolt (shown in the first photo) is inserted through the side which pins the lower between the two sides of the upper. This makes for a very easy installation.

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progress 005.jpg (583603 bytes)     Progress 004.jpg (822111 bytes) Headers/Exhaust/O2 Plumbing:  The EEC requires HEGO (Heated Exhaust Gas Oxygen) sensors to be mounted in the exhaust system.  These sensors monitor the oxygen content of the exhaust and signal the EEC as to the 'leanness' or 'richness' of the exhaust.  Threaded "Bungs" must be welded into the exhaust system to screw in  the sensors.  When stock early model manifolds are used, the O2 sensor needs to be welded into the exhaust pipe near the attach point to the manifold.  Late model stock manifolds do not fit the early model engine bay.  I used Steve Ainsworth's (Ultrastang) method of using 18mm spark plug anti-fouler as the bungs to weld into my Hedman long tube headers..  Instructions



Engine Installation:   
The following photo depict the 5.0 installation.  Nothing special about this motor/transmission installation.  Having an engine leveler is a very handy device when stabbing the complete assembly.  I used the two lifting ears that came on the 5.0, and bought two more from Summit (front ones). Note the shifter on the T-5 is not installed.  It is difficult to clear the tunnel with the shifter installed.  My assistant guided during the up-back-down-forward endless circle to get the assembly in. The remaining photos show the motor in place and some of front accessories installed.
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Engine Completion:
Removal of EGR:  Since I had removed all the smog items from the 5.0, I also did not install the EGR assembly (between the upper intake and the throttle body).  The EGR system is designed to recycle burnt gasses back into the intake for better emissions, and an engine coolant circuit is used to cool the intake.  I removed the EGR assembly from the end of the upper intake and removed the threaded rods.  I purchased a 1/2" billet aluminum spacer place, which functions to block off the upper intake and also to provide mounting points for the throttle linkage bracket.  This plate (right) was purchased off Ebay for approx $20, and can be found in various widths.  I chose the 1/2" width because I needed something as short as possible in order to use the factory rubber MAF snorkel.

Along with removing the EGR assembly, the coolant lines must be removed, and the two coolant ports plugged.  the rear intake port can use a standard threaded plug.  The forward line attaches to the 3/8" port on the upper coolant tube.  I filled the port with high temp RTV, and then installed a small rubber plug on top and secured with a hose clamp.  An alternative is to braze shut.

The removal of the EGR requires a "dummy signal" to fool the EEC into thinking it is still in place.  A EGR eliminator plug can be purchased from FordFuelInjection for approx $20, and will complete the circuit and keep error codes from being produced.

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                        004.jpg (822111 bytes) Throttle Linkage:  The factory 5.0 Mustang throttle linkage is a good choice for the early model transplant.  The factory linkage is long enough to reach from the throttle body on the passenger side (left photo) to the proper location on the firewall over the gas pedal (right photo).  Note: Because the EGR spacer was removed, the throttle body is moved effectively 1.5" inboard.  The throttle attach bracket will not mount to the billet spacer because it interferes with the coolant tubes.  The throttle attach bracket must be modified to clear the obstructions. For a gas pedal, I used a standard 1970 pedal, and modified the upper end to reach the throttle cable.

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Serpentine Belt Mount:  Note in the photos of the donor motor above, there were no accessories.  Kind of a blank slate.  There are SO  many choices regarding belts depending on what you currently have, and what options your car contains.  Since I did not have A/C or PS, I was left with the typical Alt-Crank-Water pump triangle.   Then the question becomes, standard or reverse rotation water pump and V vs Serp belt.  Changing to a V belt would have meant getting another harmonic balancer that was correct weight with a 3 bolt pattern.  It also would have meant changing to a different timing cover and a standard rotation water pump.  Too much cost.  In the end, I chose to leave the timing chain cover and reverse rotation water pump as is, and run a OEM serpentine path minus the AC, Smog, and P/S.  These missing items required the addition of an alternator mount, and an idler pulley mount.  I chose a March alternator mount and a Trick Flow Idler pulley mount.  March makes both, but the Trick Flow is about 25% cheaper.  (But the March would have matched). By using the TF bracket, the idler pulley moves over to replace the A/C and P/S pulleys in the circuit. I also installed a high volume polished water pump. The belt is a Goodyear Gatorback; I believe 59".   Also,  you will need to get another Idler pulley that is grooved.   Check Summit for best pricing on the brackets.

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Heater Hoses 

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Heater Hose Routing:  The donor  5.0 motor has the standard metal heater tubes which run the length of the pax side of the intake.  This is a much neater looking system than the old heater hoses.  To attach, I chose to use pre-formed heater tubing to attach these lines to the existing heater core, as well as clean up the appearance of the installation.  In the top left photo, note the close positioning of the tubes to the firewall.  I took the area measurements and headed to the local autoparts store to cruise through the hose racks, looking for suitable bends. After several tries I found two hoses that had bends within them that fit the situations.  I took these, and cut out the useable bends, and attached to the heater tubes.  This left a portion extending inside the firewall.  To connect to the heater core, I used straight hose, with a straight line coupling. (lower left photo).  In the end, the installation fit very nicely.  (Click photo at right for a larger view).  When choosing donor hoses for their bends, choose carefully.  The formed hoses are expensive and the autoparts store will not take them back once you've cut them up. Update: Per Corky: Use a Gates 20662pn 90d 3/4-5/8 hose on the lower(3/4) tube, then use a Gates 28625 90d 5/8x5/8 hose connector to splice/connect the lower heater hose coming from the firewall. The upper heater hose can be used with no splice.
What a time & headache saver!!

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Radiator Hoses:  Once again, installations will vary based on the size/type of radiator and the upper intake location.  I have an AFCO aluminum radiator installed, which moves the upper hose location further to the passenger side.   I also use an in-line Tefba filter to keep debris out of the radiator.  To mate the motor and radiator,  I used a standard Mustang 5.0 upper radiator hose, and spliced in the filter at the most optimum point.  Had I not had the inline filter, I would have still used the stock hose, but cut and inserted a piece of steel tubing to adjust the distance.  The lower radiator hose outlet on my radiator is on the driver's side (same as water pump).  I used a standard flex hose to fit.  While not as visually pleasing as the pre-formed hoses, the universals come with a steel spring which keeps them from choking down during a strong coolant vacuum.
Speedometer Cable Modification:  In order for the EEC to sense a deceleration condition, it has to be connected to the transmission.  Pins 3 and 6 of the EEC are connected to the VSS, or Vehicle Speed Sensor.  This sensor is mounted to the transmission end of the speedo cable.  (See photos right).  To mount the VSS, remove the plastic speedometer gear from the end of the cable and cut off the end of the housing.  Some people cut off a portion and drill up the end of the VSS to fit.  I removed the total end of the cable housing, leaving the end of the speedomer cable. then I drilled a small hole in the end of the VSS.  This allowed me to insert the end of the cable into the end of the sensor to engage the internal mechanisms.  The to pieces are secured together using RTV and a hose clamp.  Lower right photo shows the assembled parts.  The plastic speedometer gear is then reinstalled onto the end of the VSS sensor.  Note: If I was to get a 'do over', I would leave approx 1/4" of the gear shaft, and updrill the size of the interior housing to mate.  This would make for a more secure alignment. Note…on an automatic transmission, installation of VSS, is only needed to prevent a code

Another option for those who don't like cutting up there speedometer cable is to purchase a completed assembly from Ron Morris.

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Starter: Best to use the late model starter.  These PMGR "Mini-Starters" are very powerful, very efficient, are smaller, lighter, and are not prone to heat soak.  It has ample clearance from the long tube headers.  Installing a mini-starter requires modifying the starter wiring.

K&N Air Filter: Another nice option is using a universal conical K&N filter (P/N RE-0920).  I have not oiled it yet, don't want it clogging the MAF sensor.

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Alternator  Wiring:  Photos at the left represent the 2G Alternator installation.  The alternator is a standard 2G 75 Amp unit.  I am not worried about the need for extreme power, as I am not running any overly power hungry accessories.  If I had a large stereo, I'd want to install the 3G.. 

Diagrams of connections, schematics, and connector views are shown here.  The wiring is fairly straight forward.  In addition to using these schematics, I am using a Ron Morris alternator pigtail. It is a very high quality product.  I did however, end up modifying the Ron Morris harness to this schematic.

In the near left photo, you can see the alternator cable, the 175A Megafuse, and the connections to the starter solenoid.  The output side of the solenoid now is connected to and fires the solenoid mounted on the top of the starter.

Export Brace and Monte Carlo Bar:  The upper intake of the 5.0 will not clear the standard bracing of a 1st generation Mustang.  The aftermarket export braces will also interfere.  There are several options on the market, but I chose to build my own as shown right.  Detailed build information can be found here.

Detailed photos of the custom Monte Carlo Bar are shown below.

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Reference Webpages:  The following webpages are good references and support the details of the installation:


Engine Launch:
The photos below are added for reference.
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FCF Test Fire View 1 View 2 View 3 Clearance