Z height problems

New here HELP PLEASE
I am running carbide motion all updated versions on a new Shapeoko XXL. However. When I’m loading a gcode from Carveco Maker+(output gcode as "carbide shapeoko) , Carbide motion thinks the z height is 3.0 inches even when the gcode shows it being 1.75.   The issue i am having is it plunged first pass on 1.78" material to .830 even with ramping set.   
Any idea

Here is the first few lines of the Gcode:

(Lion Star base NEW6)

(STOCK/BLOCK) (X=14.500, Y=10.500, Z=1.780)

G90 G94

G17

G20

(Tool Number:1 0.250 inches dia. slot drill)

G28 G91 Z0

G90

T1 M6

S18000 M3

G54

G0X0.0000Y0.0000Z2.0000

(Machine Relief)

G0X0.0000Y0.0000Z0.0000

G0Z2.0000

G0X-7.2500Y-5.2500

G1Z-0.0573F10

G1X7.2500F60