sway bar upgrade on 2002 F-350 dually

I have a 2002 F-350 Crew Cab dually 4x4 with a diesel and have both front and rear Hellwig bars and weigh about 12k loaded. They help in corners and make the truck feel more tied together. It was a noticeable difference but not huge. The rear bar is not stiff enough for my liking. I still get rocking pulling out of uneven driveways. Truck Camper Magazine had an article that mentioned just this problem when they had bars installed on their rig. I believe it was Roadmaster they used. They were able to get a slightly thicker bar from another application that made a huge difference for them. I have not taken the time to research larger bars for my truck. I guess I should mention I started with factory bars front and rear before installing Hellwig.

I have front and rear Hellwig on a 95 F-150 2wd regular cab short bed that came from the factory with no bars. MASSIVE improvement and 100% satisfied. Just backing out of the driveway I could feel the difference in stability.