First it depends on if the trannie type in the PCM is the same as your car.
Best is to download that PCM, see what trannie it is and also what the code segments are. Its possible it has new patches in it or maybe really old ones.

Best of course is to do a full flash with all software segments with newest GM code segments whichs assures problems they fixed are in the flash used

If the flash is emailed to me I can tell everything about it.

The PCM was configured for a different vette so its possible when you use it in your car it may need a PCM to BCM relearn, which also resyncs the code for VATs and also may need a crank sensor relearn done to sync the rotation of your sensors code into the PCM being put in

BCM / PCM relearn can be done manually, CKS relearn requires a scanner or Tech-II to send the relearn command.

If the PCM/BCM are not sync'd the car may not even start as BCM as a different key VATs code thus relearn must be done

If CKS is wrong then there will be a ton of misfires, esp at startup/idle.

You could get away with having a different VIN # in the PCM, best case of course is to force flash and change it to match car

Do not believe the BS that no relearn has to be done, best case it do the relearns to assure all modules marry and sync up.

Use search on this forum to fine the PCM/PCM relearn which takes about 33 minutes of key on/off cycles.

CKS must be done after that and is done at idle bouncing off rev limiter while scanner is sending the CKS relearn command