use your original engine harness, cut and splice the OBD2 injector plugs, extend IAT plug, remove the CKP on the oilpump, cut and splice the OBD2 harness dizzy plug to your old harness. thats about it, this is how i been doing swaps for years with zero issues
this method worked for me id say once or twice, after that it never worked for me ever again LoL.. hence why i prefer the original harness mod method