* Size and Weight: The 350 is considerably larger and heavier than the Bronco II's original engine. This necessitates significant modifications to the engine bay, possibly including body modifications. You'll likely need to modify or replace the firewall, and possibly even the front suspension.
* Transmission: The original Bronco II transmission won't likely handle the power of a 350. You'll need a stronger transmission, likely a TH350, TH400, or a more modern automatic, along with the associated adapter plates and modifications.
* Driveshaft: The driveshaft will need to be modified or replaced to accommodate the new transmission and engine.
* Exhaust: The exhaust system needs to be completely fabricated to fit the new engine.
* Cooling: The stock Bronco II cooling system likely won't be sufficient for the larger engine. An upgrade will be necessary.
* Wiring: The wiring harness will need significant modification or replacement to integrate the 350's electrical system.
* Mounting: Engine mounts will need to be custom fabricated.
In short, this is not a project for a novice mechanic. It requires significant fabrication skills, welding expertise, and a deep understanding of automotive mechanics. Many custom parts will be needed, adding significantly to the cost and complexity of the project.
While it's *doable*, it's a substantial undertaking that requires a considerable investment of time, money, and expertise. It's much more involved than simply dropping in a replacement engine.
