Let me refresh your memory then on what you wrote to Second Chance who said 13'6" was the legal height. You took issue with his post stating someone had informed him wrong. Here's what you wrote:
"You had someone inform you wrong.
13.5ft is the maximum height before you are considered an oversize load that requires permits for each trip."
So now you're saying Second Chance wasn't wrong? Apparently so after you understood the conversion of 13.5 to 13'6".
Obviously when you were so quick to tell Second Chance he was wrong about 13'6" that you weren't doing your math and realize that 13.5' is exactly what Second Chance said at 13'6". Second Chance wasn't told wrong by anyone. His post was correct. It's you who couldn't understand the conversion and then was so quick to jump on him.
As far as what is "limiting because once you get off the roads and into RV parks, no guarantee you will have even 13.5ft." is a bogus argument and has nothing to do with legal height. Once you get on private property like an RV park there's no telling what over hanging objects will be encountered. But that has nothing to do with the discussion of what is legal.