* Mounting: The engine mounts are different. The Mustang's 4.6L is designed for a smaller, more compact engine bay, while the F-150's bay is larger and built for heavier-duty engines, often with different mounting points. You'll need custom engine mounts fabricated.
* Transmission: The transmissions used in Mustangs and F-150s are different. Even if you find a Mustang transmission that *could* work (unlikely to be a direct swap), you'll need a custom adapter plate to mate the transmission to the 4.6L engine. Further, the F-150's drivetrain components (driveshaft, axles, etc.) may not be compatible with the Mustang transmission's output.
* Wiring Harness: The wiring harnesses are completely different. You'll need to either extensively modify the Mustang harness to work with the F-150's systems, or create a custom harness. This is a complex undertaking requiring significant electrical knowledge.
* Computer (PCM): The Mustang's PCM is tuned for the Mustang's specific systems. It won't work correctly with the F-150's sensors, actuators, and other components. You'll need to find a way to either reprogram the Mustang PCM or use a standalone engine management system.
* Exhaust: The exhaust system will need significant modification or complete replacement to fit the F-150's chassis.
* Cooling System: The F-150's radiator and cooling system might not be adequate for the 4.6L. Changes may be needed.
* Accessories: Power steering, alternator, and A/C components might need to be adapted or replaced to fit the F-150.
In short, while technically feasible, it's a very involved and expensive project that requires significant mechanical and electrical expertise. Unless you're experienced in engine swaps and custom fabrication, it's likely not a practical undertaking. It would be far simpler and cheaper to find a used engine that's a direct replacement for the existing F-150 engine.
