anti theft light

Hi everyone. I have to change out the ECU and BCM on my torrent. I have a parts car. I was just wondering if I should also swap the ignition cylinder lock as well? Would that make the computer and theft systems work or would I have to reprogram the keys doing the 30 min reset ?

2004 Grand AM My anti theft light went of the other day, I stopped turned off the car. Every thing ran great. Then yesterday the car is dead. Can't jump it, deader than a door nail. I have juice in the battery. The alternator is good. How do I get it running again? heck I never new there was...