Essentially you just need power to the starter, spark at the plugs, and fuel through the injectors to make the engine run in any car. But to do what your asking isnt very hard, lots of people have done it before. It depends alot on what ecu your going to run. If you have just the engine, then the stock connectors should work for most of it minus the TPS as thats different. injector plugs should be the same. The alt connector is different (unless your not going to run the FD alternator). The MAP or MAS is going to be different if your even going to run the stock air metering system for either platform. Im assuming your bolting it to the FC trans? I have heard before that there is a difference between the FC and FD trans as one is a push system and one is a pull and its a slight pain to convert? But i have no experience with that.

The other thing that may be of concern is your turbo manifold and turbo selection. If your going to run the twins, you need to make sure that you have clearance between the twins and the fender, on the passenger side. Some people have issues running the FD manifolds in the FC and some dont. Im not sure why theres a space issue, but you should go ahead and make sure that its all gonna fit nicely before you get ready to drop it in.

Ill scoop up some links on the swap in a lil bit when i get some time to grab em