Adjusting Elevation of Contour lines

[remington429 0]

Is there a way to adjust the precise level above sea level of contour lines based off of a point cloud?  I know what height the lines should be at and they are consistently registering almost 600 feet higher than they should.

[BIGAL 503]

The best way is to change your point cloud Z's but that may be hard.

or

To Change the Elevation of a Surface | Civil 3D 2019 | Autodesk Knowledge Network