Got a snorkel and a tarp....... will travel!
If done correctly, you should have no problems at all.
The stock air box air inlet is just behind the LH head light, I measured my XJ, and to the top corner of the guard is 1050mm. I have a 3" lift, so 75mm from 1050mm is 975, and about 100mm down again to the inlet, so you have 875mm. But may be they don't measure to the air box.
Just my idea.