Perfect! Thank you :) I may picking up an hard shell RTT over the weekend and giving these a try.I used these:
Air Lift Bags
This was based off info from a guy off the AEV Forum, the width is perfect but they are a little tall, maybe a 1/2" extra. That said, I've had zero issues with them. I will suggest pulling your springs to install them, I tried to slip them in as the directions suggested and I can tell you that was a waste of a good hour.