I have a dug out earthen basement that has very uneven floors. I placed a laser level and measured all around the basement. There are some high spots and low spots. 1.75in disparity all around. Aside from the high and low sports, the concrete pour is very crude and unlevel.

Basement has had water events in the past. These have been dealt with with a interior drain tile solution, but I digress. We want to put tile down and am not sure what is the best way to move forward.

Should I do a self leveling pour to flatten our the floors? Can I just accomplish this with building up thin set, underneath? Looking for some guidance.