Is it compatible

I was wondering if a 97 buick lesbre 3.8 motor is the same as a 97 buick regal 3.8? motor looks the same. if i did the swap will it work and run without a problem? do i need to do a pcm/ecm swap also?

The engine should be the same; however, the final drive ratio of the transaxel would need to be the same on both cars for the PCM to work. Your PCM is programed according to the final drive ratio. If you change only the engine, your original PCM should work fine.