* Mounting Points: While the general engine block shape may be similar, the exact placement of mounting points might be slightly different. This could require modification to the engine mounts or the car's frame.
* Wiring Harness: The wiring harness from the 2009 engine will almost certainly not be compatible with the 1999's ECU and electrical system. You'll need to adapt the harness or source one from a similar-year Crown Victoria.
* Sensors and Emission Controls: The newer engine may have different sensors and emission control systems. Compatibility issues are possible here, leading to the need for modifications or replacement parts.
* Accessory Drive: The arrangement of the alternator, power steering pump, and other accessories might differ. You may need to swap these components or adapt them.
In short, while the engine *might* physically fit, a considerable amount of fabrication and electrical work will likely be required to make it function correctly. It's a significant undertaking, not a straightforward swap. You'd need a good understanding of automotive mechanics and potentially a professional's assistance.
