* Motor Mounts: The 4.6L has different mounting points than the original Fox-body Mustang engines. Custom motor mounts will be required.
* Transmission: The transmission will need to be compatible with the 4.6L. This likely means sourcing a suitable automatic or manual transmission and adapting it to the Mustang's existing drivetrain components.
* Wiring Harness: The 4.6L's wiring harness is completely different. You'll need a custom harness or significant rewiring. This is a complex task often requiring specialized knowledge.
* Exhaust System: A new exhaust system will be needed.
* Cooling System: Potential modifications might be needed to the cooling system to ensure adequate cooling for the 4.6L.
* Fuel System: The fuel system might need upgrades to support the 4.6L's fuel requirements.
* Computer Control: The 4.6L uses an electronic control system. You'll need a compatible computer and potentially other electronic components. This aspect is often challenging for experienced mechanics.
In short, while it's *possible*, it's a substantial undertaking requiring mechanical expertise, fabrication skills, and specialized tools. It's not a weekend project. Many people opt for using a harness and computer from a similar-year Ford vehicle that's known to be compatible, significantly reducing the wiring challenge but still demanding skill.
