Need to lower my Lift.

[CAB85]

Hello everyone! 

I drive a 2014 Sierra Z71. I want to lower my truck some because it's a little to much right now. I'm having a hard time finding consistent info that I need.

I need to fit 33x12.50R20s on a 9inch wheel with a -1 offset. 

I have the Bilstein 5100s and this spacer.(I was told that the 1in spacer will actually lift 1.5in, not sure if that's true or not.)

 

If have have the Bilsteins on the second notch that is a .75in lift plus that spacer will my tires fit?

I can adjust the Bilsteins from stock, .75, 1.25, and 1.80. I believe. 

Thanks in advance.