My 2006 pleasure way lexor TD on a chev was 8'10" as std, with the ac being the highest point. me adding a cover over the vent takes it up to 9'4".
I measured with laser level laid on highest point and holding measuring tape from ladder...add a couple of inches and a P-touch label on my outside mirror
your clearance may be more restricted if the approach is not level.
story in my family of my brother-in-law who used to zip through his local fast food drive through for years...until they laid in 3 or 4 inches of asphalt when repaving driveway.
it cost him about $50K on damages to his van ( not covered by ins.) and to the drive through overhead
mike