For me, it's simple. Parts - Mass air meter of your choice and bracket that bolts to strut tower. Air inlet or the cold air induction kits that all the kids use these days. Used or remanufactured EEC-IV. MAF harness connector cut out of another Ford vehicle (doesn't have to just be a Mustang). Some length of wire along with the harness. Cut out the main EEC connector to the computer from another Ford vehicle so you'll have pins with wire to spare. You'll remove the old EEC from the bracket. Seat the newer one in place. Add & move required pins around inside EEC main connector and solder wire ends together to the MAF harness and connect to MAF sensor. Connect main connector to EEC and disconnect the hose to MAP sensor on firewall. Cap off the hose that came off the MAP sensor and start the car.

A lot simpler than spending hours removing wiring in the engine bay and figuring out where the hot leads are for gauges, ignition, etc., etc. for a carburator conversion. You do the conversion that is best suited to you and/or your personal knowledge. Converting a speed density is easier for me and it's my opinion to stick with EFI if I were in your place because it's already there.