* Motor Mounts: The Chevy 350 and Buick V6 (likely what's in the Regal) have different motor mount patterns. You'll need custom motor mounts or an adapter plate.
* Transmission: The Regal's transmission likely won't bolt up to a Chevy 350. You'll need a compatible Chevy transmission (TH350, TH400, 700R4 are common choices) and associated driveshaft modifications.
* Exhaust System: The exhaust system will need to be completely fabricated or significantly modified.
* Wiring Harness: The electrical systems are completely different. You'll need to either modify the existing harness extensively (a very difficult task) or use a wiring harness designed for a Chevy 350.
* Cooling System: The radiator and hoses may need replacement or modification to accommodate the different engine.
* Computer Control (if applicable): Depending on the year of the 350, you might need to deal with the engine's computer control system, which will likely be incompatible with the Regal's wiring and systems. This can add significant complexity.
* Steering and other components: Depending on the size of the engine and accessories, you might need to make modifications to the steering shaft and other front-end components to provide clearance.
In short, while it's *possible*, it's a major undertaking requiring significant mechanical knowledge, fabrication skills, and likely custom parts. It's far from a bolt-in swap. It's often cheaper and easier to find a Regal with a V8 already installed, or to use a Buick V8 that's more readily compatible with the existing chassis.
