My 2013 2 door Rubicon has a full Rock Krawler X-Factor 2.5" lift with 35" tires. On the modified obstacle course at Jeeptoberfest, the passenger side front tire was rubbing slightly on the inner fender. It seems as though the passenger side is 1" lower than the driver side. Is it normal to have different ride heights by as much as 1"? Should I consider putting a spacer in to level left to right?

 

Possibly your axle not centered under the jeep. If you have an adjustable trackbar, you can adjust it accordingly to take out side-to-side discrepancies. Atleast that would be the first place I look.

 

+1....that goes for both front and rear TBs. That is the first place to start at least.

 

The fuel tank and battery are both on the right side so it should be lower, how much depends on suspension. They do make spacers that are 1/8th inch for that reason.

JK Front Coil Spring Spacer Set (metalcloak.com)

JK Rear Coil Spring Spacer (metalcloak.com)

 

you could always put a bit of preload into the sway bar with adjustable links.

 

This keeps coming up as reasons for a low right side.

There are things on the left side that balance the fuel and battery: front drive shaft; transfer case; steering wheel and steering box; to name a few.
When I weighed my JK with a scale under each tire, tank half full, no one inside, the left and right sides were equal.