If you swap BEM (Body Electronic Module) you first have to download the electronic lock assembly code into the BCM for the car to run, The procedure per section 15-8-3 of the factory workshop manual for the EF is:
1.Turn off all accessories.
2. Scan for error codes and remedy and clear any error codes (See Ford Ford EFI - pictures of diagnostic connector locations
or contact the seller to buy one of these FORD Falcon XF EA EB ED EF EL XG XH OBD1 Fault Code Reader Diagnostic Unit | eBay
he makes them on order ) for how. Note these old Falcons from ED to AU have non compliant OBDII systems so most less expensive generic code readers won't work with them.
3, The Smartlock light should now be flashing the red armed code.
4. Turn the ignition switch to the "RUN" Position. The warning jewel should now flash error code 3, then the car immobilized code.Leave the ignition switch in the "RUN" position for 30 minutes.
5.After the 30 minutes, the electronic lock assembly codes will download into the BEM and the door locks will cycle twice before the warning light extinguishes.
6. Turn the ignition switch to the "OFF" position for at least 30 seconds and until the warning jewel flashes the armed flash.
7. Without removing the key, start the engine.
Also check that you have a 6mm spark at the plug end of the HT lead. Just a spark won't suffice; it needs to be strong enough to jump at least 6mm for the car to start and run (It will usually jump at least 30mm in a car with a healthy ignition system). Best checked with one of these tools Toledo Spark Plug Firing Tester Heavy Duty 302167 - 302167
or Toledo Ignition Spark Tester Box Type - 302165
Don't try the screwdriver to head trick; the spark in these ignition systems is strong enough to give you a heart attack! The car's ECU turns off the fuel injection system when there is insufficient ignition spark to a) prevent a build up of fuel in the intake and exhaust system that could eventually ignite and explode catastrophically usually breaking at least the air cleaner box and some of the plastic intake parts; and b) prevent raw fuel accumulating in the catalytic convertor and destroying it.