What doner car you got? a granny is better cos the engine loom is seperate from the cars main loon and comes out in 1 peice.
You'll need to alter the fuel outlet on the tank to take the injection pumps larger bore pipework and plump in a fuel return from the fuel rail (use and RS or ghia fuel sender as they have a fuel return as starndard.
If you need help wiv the wiring let me know cos i'm in the process of injecting a cortina and have a few looms laying around teh garage