I don't have an answer for you.
However, I would be concerned about the additional weight and the impact on the COG.
Are you planning on filling the tank at home and driving to your destination or filling near your destination?
You'll have a little over 400 pounds with the weight of the tank.
But, once you start bouncing down the road the dynamics will change quickly. And momentarily you will have much more than 400 pounds which could be the straw that breaks the camel's back.
It may also affect the handling of your RV.
I would carry 5 gallon jugs inside the RV, you can store them outside
When you get to your destination.
