How hard to swap my 2000 3.8 camaro with s10 2001 4.3 what if I use pcm that goes with motor

Not really worth it, the PCM would need custom programming and that itself is very expensive, let alone all the other headaches you'd be dealing with. Just find another 3800 out of a Firebird/Camaro if yours is shot.

What if I use the pc that goes with motor