Not sure I ever drove my rig this way before, sans roof rack. But the need arose when I had to get into the parking garage at the Seattle Airport parking garage….
While the garage is 6′ 10″ tall my rig with rack is 7′ tall so this was a good reason to know just how tall my rig is. The best way to measure this on your rig is to put a stick across the tallest part of your rig and measure down to the ground. Then you will forever know a baseline height of your rig. Of course loaded weight and low tire pressures will change this but you will have a good starting point when you see that low clearance sign just before you crunch something important.
I also felt it best to remove my CB and Ham radio antenna’s. I hate that sound as they drag across the concrete of a parking garage beam. The other possibility is that they might not bounce back if your mounts are extremely rigid, which is how mine are set up.
But alas all is not lost as the rack is once again on the top of my rig. Just no way to go camping without that rack!