* Engine mounts: Completely different.
* Transmission: Probably incompatible.
* Wiring harness: Requires extensive rewiring.
* Exhaust system: Needs to be completely refabricated.
* Cooling system: Likely incompatible.
* Steering components: Potentially interfered with.
While technically *possible* with a tremendous amount of custom fabrication and engineering, it's not a practical or cost-effective swap. It would be far easier and cheaper to find a used 3.8L Impala or a different car with a 3.8L engine altogether.