point me in right direction

Get the trailer loaded and use a tape measure?

 

Ride height for what kind of trailer?

 

https://aus.hendrickson-intl.com/ge...33d303f1769/L459-Checking-Trailer-Ride-Height

 

This was just a quick Google search. I just typed “Great Dane trailer ride height specs” and that was the first site that popped up. Not sure what suspension you have .

 

If you have ‘air ride suspension’ the ride height should be close, loaded or empty.
Spring ride, that’s a different ballgame.

 

"Should be" and trusting written information based on perfect situations can potentially screw you. There was somebody posting a few months ago, he'd struck an object and was ticketed for over height. According to all the information he had, minus doing an actual measurement, he should have been legal.

 

I take it you are needing the height of the top of the trailer? Not the height of the ‘levelness’ of the loaded trailer sitting on a fifth wheel( from the ground up to the bottom of the trailer).
Anything over 13’6” is considered ‘over height’. Time get a tape measure.