The 2G GST tranny is NOT the same as the ESi/RS/GS/Avenger/Sebring/Neon/etc. That's like asking if you can just drop in a 4G63 in a 420A DSM lol
They are completely different setups. They even sit on the opposite side of the engine bay. They are not made by Mitsubishi. The code is NVT350 for these transmissions.
Rob hit the nail on the head regarding wheelhop. If you want the most out of it and want to eliminate wheelhop, better mounts are a must. I went from wheelhop glory to virtually zero when I installed Prothanes in my old 1G FWD. Just get used to stuff rattling.