Hello,
I also own 5.7 Grand Cherokee (overland - with air suspension).. I am sure that the engine is a beast and will perform excellently in desert (have done a bit). I guess you only need to remove the front air dam for offroading.. If you drive carefully then the car has enough ground clearance to get you through..
Regards
Hello, This is Dheeraj here.. I am living in Dubai for last 7 years.. Currently driving a 2012 JGC Overland.. Nice to see a Dubai based Jeep community..