Ron Morris Performance is your Mustang and Bronco EFI Conversion Specialist!

1001 Reno Avenue, Suite 2 F, Modesto, CA. 95351
FAX 209-569-0558

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   Most of the information contained on this page will be directed toward Mustang and Bronco conversions. If you are performing a swap on a different model vehicle, then some of this information may not apply.

    If you are installing a complete EFI engine from a late model donor car, into an early Mustang or Bronco, you will need to change the oil pan. You will need to install the correct oil pan for your model vehicle.

    If you are doing an Early Mustang EFI Conversion and installing a late model engine into it, then relocating the dipstick and dipstick tube to the timing cover will have to be done. You will have to drill your timing cover. The 86-93 engine timing cover has a place for the dipstick, it just needs to be drilled. The 94-95 timing cover does not have a place for the dipstick.

    The 94-95 Mustang timing cover is different than the other timing covers. There is NO place for the dipstick to be installed. This timing cover is shorter than previous timing covers and requires a special water pump. The accessory brackets for these engines are different also. These brackets and water pump move all the accessories back toward the engine. This is great for extra radiator/cooling fan clearance, but if you plan to run air conditioning, you will run into problems. The air conditioning compressor will come in contact with the shock tower. I have heard that it is not even possible to install the compressor on the bracket.

    There are many different intake manifolds out there to choose from. Mustang intakes are great for a good running stock engine. Explorer intakes are one of the best intakes available, They provide excellent performance for stock and modified engines. The factory Explorer EGR spacer will not work in Mustang or Bronco conversions, it is a 90 degree spacer that puts the throttle body pointing forward. It should be replaced with a Mustang EGR spacer or an  RMP EGR eliminator kit.

    There are also many after market intake manifolds available that will work just fine for your EFI conversion. Ford Racing Performance Parts, Trick Flow, Edelbrock, Holley and Weiand, to name a few.

     If you are wanting to fuel inject a 351W (5.8L), then your manifold selection is limited. Ford Racing Performance Parts, Trick Flow and Edelbrock all make intake manifolds for the 351W.

    If hood clearance is an issue with your EFI conversion, use these dimensions to determine which intake is best for you. These measurements are made from the bottom of the intake manifold, where it meets the block, to the top of the upper intake manifold.
                                              1986-93 Mustang Intake Manifold  11 inches tall
                                              1994-95 Mustang Intake Manifold   9.5 inches tall
                                              1995-2001 Explorer Intake Manifold  11.5 inches tall   

    It may be necessary to replace the exhaust manifolds or headers of your swap engine. You will need to install headers or manifolds for the model car that you are installing your EFI engine into.
Late model Mustang shorty headers will not work in an early Mustang or Bronco. You could use your stock exhaust manifolds, shorty headers or long tube headers with an EFI conversion. Which ever you decide to use, just make sure that the O2 sensor is installed so that it can sample exhaust from all cylinders on that one bank.

    Another thing to remember when doing an EFI conversion is that there is 2 different firing orders for small block Fords. Early 289's, 302's and some late model 302's run the 15426378 firing order.  Late model 302 HO's and 351W run the 13726548 firing order. Installing EFI on the 15426378 firing order is possible, but does not yield the same results as the late model HO firing order. When you mix, match these firing orders you may encounter some driveability problems like poor idle quality. The Mustang EFI system is a sequential fuel injection system, which means that the injectors are fired in a firing order just like the spark plugs. Mixing these firing orders (spark plug & injectors) can cause a rough idle and poor driveability.
    If you are building an engine for an EFI conversion, make sure that the cam you install has the 13726548 firing order.
    Some people may tell you that all you have to do is rewire the injectors to change their firing order to match your cam or engine. I can tell you from experience that this does not work, it causes erratic fuel control, back firing thru the inatke manifold (at times), rolling or hunting idle and poor driveability overall. I learned the reason for this once I started reprogramming PCM's for different engine modifications. In the Cal Edit Software there is a table called Exhaust Pulse Delay, what this means is that from the time the #1 injector sprays fuel into the #1 cylinder it knows how many crankshaft revolutions it will take before that exhaust (fuel) passes the bank 1 oxygen sensor and so on for every cylinder of that engine.
    This also explains why installing long tube headers can cause idle and driveability issue too.

    Ford EFI systems require TFI distributors. (Thick Film Ignition) 289, 302 and 5.0 distributors are the easiest to come by. 351W distributors are a little harder and more expensive to buy. If you are looking for a better appearance than a stock distributor, both ACCEL and MSD make billet distributors for the 289, 302, 5.0 and 351W.
    If you are considering fuel injection for a 351C, A customer told me that a 460 distributor will fit in a 351C block and the 460 came from the factory with EFI. So this would be the distributor to use for a 351C and 460 EFI conversion.

    This is the easiest engine and EFI system to install for an EFI conversion, if you find a good donor car, most of the parts are reusable. Parts needed are throttle pedal, throttle cable, computer(pcm), all engine mounted EFI parts and sensors, MAF sensor and the wire harness can be modified for your EFI conversion if it is not damaged. The 86-88 (federal) and 86-87 (california) models are speed density EFI systems, that can easily be converted to mass air systems with a mass air EFI wire harness and PCM. If you are looking to increase the output of your engine, than you will need to go with the mass air system.
    These intakes have internal EGR passages, so if your conversion must be smog legal, this is a good intake to use, no extra work is needed. If you do not want to run the EGR system, it can be removed with the RMP EGR Eliminator kit.

    This is a good engine, computer and wiring system for an EFI conversion. It uses a 2 speed electric cooling fan, an electronically controlled automatic transmission (AODE) and has data link capabilities.
    If you are installing this engine into an early Mustang, the timing cover does not have a place to drill for relocating the oil dipstick tube. The timing cover that comes on the 94-95 Mustangs is shorter than 93 an earlier timing covers and has it own water pump and accessory brackets. If you decide to change the timing cover you will also have to get different accessories and brackets. If you plan to run air conditioning, you will have clearance problems using the stock 94-95 brackets and a/c compressor. The compressor will interfere with  the shock tower.
    This engine uses an external EGR tube and since the factory headers will not work in early Mustangs or Broncos, it will require some fabrication to tie this tube into your headers or exhaust system. If you do not want to run the EGR system it can be removed with a custom chip or tuning device like the TWEECER.
   This engine also has a different distributor than the 86-93 engines, it uses what ford calls a closed bowl distributor and a remotely mounted TFI ignition module.
    The main reason for the horsepower decrease in the 94-95 engines (215 HP) compared to the 86-93 engines (225 HP) is that Ford had to go to the 89-93 T-bird intake manifold to clear the reduced hood clearance on the new body style Mustang. This new lower intake manifold has smaller runners and a smaller plenum area causing the reduction in power.

    These are good donor engines, but use the speed density fuel injection system. They can be easily converted to the mass air system with a RMP EFI Wire Harness. They will require some of the same changes, oil pan and pickup tube for the vehicle you are installing the engine into. Drilling of the timing cover to relocate the dipstick and tube.
    Some of the engines have the other firing order (15426378), which may cause some driveability problems and poor idle quality. The cam can be changed to a HO cam or most after market cams to get the better firing order. (13726548)

1995-2001 EXPLORER 5.0 ENGINES
    The Explorer engines have the best intake manifold, it is great for a stock or modified engine. When run in a dyno test against the Cobra Intake manifold and many after market intake manifolds, it performed just as well as if not better than the other intake manifolds. Explorers come from the factory with 65mm throttle bodies, but require a linkage modification when installing them into Mustangs or Broncos. When using this engine, it is best to convert to the 89-93 Mustang wiring and computer system.
    The Explorer uses a distributorless ignition system and EEC V fuel injection system. This EEC V system has a great deal of emission control devices and is difficult to work with in an EFI conversion.
    I recommend changing this to a 89-93 Mustang ignition and EEC IV fuel injection system. The EEC IV system is easier to install and has a lot less emissions equipment.
Early Explorer engines (1995 to 19971/4) came with GT-40 Heads, easily indentified by the 3 vertical ribs on the front and rear of the heads or the "GT" cast into the corner of the head just outside the valve cover. These heads have stock spark plug angles, location and will work in Early Mustangs with all common exhaust systems.
    The Late Explorer engines(19971/4 to 2001) have GT-40P cylinder heads, easily identified by 4 vertical ribs on the front and rear of the heads or the "P" cast into the corner of the head just outside the valve cover.  These heads do require special headers, they have a different spark plug angle & location and may interfere with your exhaust manifolds or headers. Check spark plug clearance before installing these heads or an Explorer engine.
    Both of these heads are great heads, they will out flow and out perform stock late model Mustang heads.

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