This is really an easy change to make. First you will need the 280 fuel tank and fuel pump. These will both bolt right in to your car. Next you need the intake and air flow meter. You will also need the thermostat housing and the sensors in it. You need to have a head on the motor with the cut outs for the injector. If the 280 motor is good, I would just bolt that right in. The 260 head wasn't cut for fuel injection.
Next you need the entire FI harness and ECU. The harness is self contained except for one plug in that goes to the main harness. You will nedd to hook those wires up separate. If you run a 79 distributer, then you can use 2 of the wires that go to the ignition module on the passenger floorboard. The other wires got to a start siganl wire and an ON position wire- both can be run right off the ignition switch. The last wire goes to the fuel pump. There are also 2 wires that go to the battery. All the other wires go to the sensors and injectors.
This is the setup I run on my car and it runs great! I even turbocharged mine. It really is nice to have the car start up right away and run so smooth. Hope this helps,