Even within the Jeep family, swapping 4.0L engines from different years can present significant challenges due to changes in the engine's design and supporting systems. A successful swap would require extensive modifications, potentially including:
* Engine Mounts: The engine block's mounting points are likely different.
* Transmission: The transmission and its interface may not be compatible.
* Wiring Harness: The electrical connections and computer systems will be incompatible.
* Exhaust System: The exhaust manifold and piping will need to be modified or replaced.
* Cooling System: The radiator and hoses might not fit.
* Fuel System: The fuel injection system might require adaptation.
In short, while the displacement is the same, the engines are not interchangeable as drop-in replacements. Such a project would be a very complex and potentially expensive undertaking, requiring significant mechanical knowledge and skills.