We chose to get all the hard parts installed first. This way you have fixed points from which you can route your electrical harness and fuel lines. The hardware in the Mass-Flo EFI system consists primarily of the modified intake manifold, throttle body and mas air sensor, as well as the various sensors and ignition components.

One look at the Mass-Flo EFI modified Victor Jr. and you get a sense of their workmanship. The injector bungs are precisely TIG welded into each runner.	As many of you know we believe power is in the details. Before we bolt this manifold on we'll take a sanding roll and smooth out the injector bungs with the roof of the runner.
We didn't have the time to fully gasket match the ports to the heads but we did clean up minor casting remnants.	The manifold also came tapped for the engine coolant and intake air temperature sensors. The ECT goes in here.
The IAT goes into the #8 runner - no specific reason it is located here other than where that connector is located in the harness.	The manifold goes into place between the heads no differently than the carbureted variety.
The injectors and fuel rails can go into place next. Use a bit of petroleum jelly on the injector O-ring. Set the injectors in the manifold bungs first, then line up and carefully push down the fuel rails. Be sure to sandwich the hold down "seats" between the two end injectors on each rail (see picture #8).	The injectors and rails are held down with the supplied brackets shown. Note the lower hold-down "seat" sandwiched between the injector and rail. The end injectors must be turned so the connector faces inward.
We've put in the 190°F thermostat recommended for the Ford EEC-IV system.	The throttle body goes on like a carburetor. It can be positioned so the linkage is on the driver or passenger side (idle air control valve at front or back.)
We found the stock mechanical throttle pedal linkage to interfere with the driver side fuel rail. Our solution was to flip the throttle body so the linkage is on the passenger side and to convert to a cable operated throttle.	A TFI (thick film ignition) style distributor must be used. If you pull a distributor from a donor EFI vehicle make sure the distributor cam gear is compatible with your cam.
Mounting a Ford TFI coil is tough without a factory bracket. We pulled this one from a Fox body Mustang and modified it to mount flat against the early Mustang fender well. All that is needs for wiring is the connector from the supplied harness. If you run an MSD 6 box then use the MSD 8874 adapter harness.	A barometric pressure sensor needs to be installed. Available new through Ford for $30, or pick up a few at a Pick N Pull for a few bucks from any Ford EFI vehicle. Take the factory self tapping screws too for a clean look. Note the vacuum port is left open because this is technically a Manifold Absolute Pressure (MAP) sensor.
The kit includes a pair of 18mm oxygen sensor fittings. These must be welded into the exhaust, ideally in the header collectors. Use any three-wire Bosch O2 sensor listed for '87-'93 5.0L Mustangs.	Mass-Flo instructs cutting a 1-1/4" hole in the air cleaner base to pass the MAF sensor connector through. This seems rather large an unnecessary to us. We simply pulled the three wires out of their connector, fed them through the existing PCV port in the base, and the reassembled the connector. There is enough slack in the harness to move the base clear over to the fender in the event you need to access the throttle body or manifold.
You'll likely need to cut a 1/2"-20 piece of all-thread to function as an air-cleaner stud. The mass-air meter must be held down using the supplied Nylock nut. This nut just needs to make contact with the meter, do not tighten it as it will crack the meter bridge.	A nice benefit to the Mass-Flo setup is more underhood clearance than with a carburetor (nearly 1/2" more.) Use the tallest air-filter you can fit under the hood. Once the lid goes on it is pretty tough to tell at a glance that this is a modern fuel injected vehicle.