The biggest difference between the two roof racks you referenced for your 2013 Infiniti JX35 is the style of feet used for the rack.
The part # RR86GR uses a flush bar style of foot which means the crossbar stops before reaching the foot of the rack. The advantage to this rack is an OEM style look that would be maybe slightly less noisy.
The part numbers # RRVA137B-2, # RRRLKVA, and # DK339 is a style of rack where the crossbar goes through the foot of the rack and comes out the other... view full answer...