If my phone is plugged in and I am using waze through carplay, the speedometer matches waze.
If I am not plugged in or connected through BT, they will read different speeds.
as @californiajeeping mentioned, Clayton doe offer a 1.5" leveling kit.
If you are looking to be closer to stock height, Clayton also offers a .5" front spring as a stand alone option. I don't remember the exact specifics, but it is a heavier duty spring then factory.