The crown bodyline is higher, which led me to think it was taller, since it wouldn't make sense to make the greenhouse taller.
According to
U.S. News and World Reports, the Crown is 3.7" taller and 4" longer, with a 1" longer wheelbase, and it weighs 770 pounds more, but has virtually identical interior dimensions, with the Crown actually having rear hip and shoulder room.
Unlike the TARDIS, it's bigger on the outside.