there is a big plug under the hood of all 96+ Explorers and Rangers, its called the C115, 42 pin plug.
This plug contains all of the wires that talk from drivetrain to truck
This is where the magic happens
If you were to build a map,
list all 42 pin locations for your truck
Then
List all 42 pins from the donor
It will become clear that only a few wires might need to be eliminated or move locations or be added to make the truck happy with the new 5.0 drivetrain
Aside from the wiring here there are only a few other small things to be addressed, like the starter and alternator harness and the AC switch wiring. You should not have to swap anything else around, no dash harness, no underhood harness, no body harness, etc.
The C115 plug is the key to all OBD2 fords 96-01!!!