These two pictures shows the most likely location of the gun with the dark grey gun port cover near the right wing root, behind the air vent.
I would be rather surprised if the gun was located there, considering putting a gun behind that auxiliary air intake would be probably a bad idea.
Also, the patent/schematic for the J-35's gun depicted it on the left shoulder rather than the right shoulder.
I would wait for higher quality pictures depicting the left shoulder.