I wasn't suggesting starting with a 4.6 car and changing the drivetrain. I was suggesting starting with a 5.0 car, and using an engine wiring harness for a 4.6 MN12, and modifying that harness to have the same pinout as the explorer ECM, and to fit the 5.0 engine. Extending the connector into the passenger compartment means every single wire has to be cut, soldered, and heat shrinked at both ends. That means probably around 150-175 solder joints and pieces of heat shrink tubing, and if you mess up one wire, you will spend a ton of time chasing the problem down. If you use a 4.6 harness, you know that the grommet is there for where it goes through the firewall, you know that the ECM connector goes to the right place, and you know that the wiring going into the engine bay has everything that you need. You would still have to unwrap the harness and lay it out to match the different motor, and some wires would need to be extended and some connectors changed, but you wouldn't have to re-do every single wire in the harness like you would to extend everything going to the ECM. Plus a lot of the wiring would land pretty close to where it needs to be anyway. The injectors are all in close to the same place, as are the TPS and IAC, and the MAF, and the oil pressure sending unit, and the coolant temp sensor, and the crank sensor, and the O2 sensors. Like I said, you would definitely have to unwrap the harness, lay everything out to where it needs to be, and re-wrap it, but most of the sensor locations are pretty close, so I don't think that would be too bad to do. As a matter of fact, this has me thinking I just might do this when I drop the new engine in the 91.