Seats, rails, etc are the same, both sides. What is different is the airbag sensors, both sides. Gen IV's have the latest bag sensors and I'm not sure if your connections will work (Also, Gen III's have the on/off switch in the center console, Gen IV's use a sensor, not a switch). I put Gen III drivers seat in a Gen IV, with retrofitting the Gen IV sensor, not sure about the reserse? Reach out to Mark J @ Woodhouse, I'm sure he can give you the best advise if the sensors will work. Good luck, Mike