I did not find a specific answer to the question in the threads so I'm here to ask what the hitch ball height is for a 21. I'll be picking mine up in a couple of weeks and that's the last question I need answered. My tow vehicle is a 2002 GMC Sierra Duramax 2500HD with stock ride height and 4wd. I would imagine I need to drop the ball a fair amount. Any assistance you can provide is much appreciated.
I towed my 21 home from the factory with a HD 2500 that had a 2000 lb. camper on it. The tongue weight of the empty trailer hardly caused the truck to settle at all and the trailer was level with a ball height of 20.25 inches (ground to top of ball). Since then I have towed the loaded trailer with a lightly loaded 1500 series truck and use a ball height of 21.5 inches to get a level trailer.
I have a 2002 Chevy 2500HD Duramax Crewcab that has about a 1/2"-3/4" sacked left rear spring. I plan to install air bags like these to deal with that plus any general drop problems before we pick our 21 up in July.
My 21' is level when the top of the ball is 22" off the ground. I don't think that we have even an inch of sag when hitched to our Tundra, so you would probably be good at 21" or 21.5". I'm told that a little nose-up is better than nose-down, so maybe even 22" would be fine?