As long as it is programmed to run a 3800SC, and the harness is built correctly, it should be okay.
Lots of swappers mix/match PCMs and engines. Just because it's a 2001(?) Pontiac(?) engine, it doesn't require that the PCM be a 2001 Pontiac piece, as long as the program and wiring have been done to accommodate.
Doesn't make it easy to troubleshoot, however. It helps if the swap was documented, which I'm pretty sure this one wasn't.