The 3.8 was a factory option in the Ciera so it will definitely bolt up, however I *think* all FWD 3.8's were fuel injected, so if that's the case it would be a major hassle. In addition to all the wiring/electronic issues you'd need the 3.8 gas tank w/ the in-tank pump, fuel lines, etc.
If you decide to do the swap, change the timing chain before you drop it in. It's really the only weak part of the 3.8 from that era, and it will trash the valves if it breaks. And it's a very easy job while the engine's out.
