* Engine Mounts: The engine and transmission are completely different sizes and shapes. The 1978 F-250 likely has a large-block V8 (possibly a 460 cubic inch), while the Crown Vic uses a smaller modular 4.6L V8. You'll need entirely custom engine mounts fabricated to fit the Crown Vic powertrain into the F-250's engine bay.
* Transmission Compatibility: The Crown Vic's automatic transmission (likely a 4R70W or 4R75W) will not bolt directly to the F-250's existing transfer case (if it's a 4x4). You'll need a custom driveshaft and potentially an adapter to mate the transmission to the transfer case, or you'll need to convert the truck to rear-wheel drive.
* Wiring Harness: The Crown Vic's wiring harness is completely different from the 1978 F-250's. You'll have to extensively modify or completely replace the F-250's harness to accommodate the engine's computer and various sensors. This is a major electrical undertaking requiring significant wiring expertise.
* Computer Control: The Crown Vic engine is computer-controlled. Getting it to run correctly in the F-250 will likely require custom tuning or a standalone engine management system.
* Exhaust System: The exhaust system will need to be completely custom-fabricated.
* Cooling System: The cooling system might need modification or replacement to ensure adequate cooling for the engine.
* Fuel System: The fuel system may need modification to accommodate the new engine's requirements.
* Brakes: The increased power of the Crown Vic engine might necessitate upgrades to the braking system for safety.
In short: While technically *possible*, this swap is a massive project requiring extensive fabrication, electrical work, and mechanical expertise. It's far beyond a simple engine swap and would likely be more cost-effective to find a suitable engine and transmission already compatible with your 1978 F-250. Unless you have significant experience in automotive fabrication and electrical work, it's strongly recommended against attempting this without professional assistance. The labor costs alone would likely exceed the value of the vehicle.
