* Engine Compatibility: The 4.7L engine was used across multiple years, so the core engine itself is likely compatible. However, there might be minor differences in accessories and mounting brackets.
* Wiring Harness and Computer (PCM): This is the biggest hurdle. The wiring harness and Powertrain Control Module (PCM) from the 2004 truck are likely *not* directly compatible with the 2002 truck's system. You'll likely need to swap the entire harness and PCM, or at a minimum, do significant rewiring. This is a complex task requiring considerable electrical knowledge.
* Sensors and Accessories: Some sensors and accessories (alternator, power steering pump, etc.) might have different mounting points or electrical connectors. You may need to adapt or swap these components.
* Transmission Compatibility: Ensure the transmission from the 2004 truck is compatible with the 2002 truck's transmission. If they're different, you'll have to sort out that issue as well.
In short, while the engine *itself* might bolt in, the supporting systems are the real challenge. This is not a simple swap and would require significant mechanical and electrical expertise. Unless you have experience with automotive electrical systems and engine swaps, this is best left to a professional mechanic. They can assess the compatibility of all the components more accurately and handle the complexities of the installation.
