I have a Superchips Flashcal for my 2015 JKU Rubicon to change tire size and gear ratio. What does the 4 high and 4 low transfer case gear ratio change do and what should I set them to with 35 inch tires and 4:56 gears. Thanks

 

All you've done is change axle gears and tire size. You don't touch the transfer case settings unless you've swapped that out for something else.
High on the xfer case is 1:1, while low is 4:1.

The original axle gears in the rubi are 4:10s. You just want to update the ratio to 4:56 and adjust for the new wheel diameter.