From my experience, these bitcoin miners are generally very stressful for the graphics card. Furmark level of stress.
I'm suspecting that your two pci-e slots are positioned with only a single slot distance between each other. Is this the case?
When you sandwich two video cards this closely to each other, it shouldn't come to anyone's surprise that the upper card gets 10-20 degrees hotter than it should. If this is the case, then you have chosen a bad motherboard.
Yeah, it sounds like the OP just doesn't have enough flow through in the case. Time to get a box o' fans.
105c is raging hot...like, burn your skin hot. I can only imagine that it'd be bursting into flames as soon as it accumulated some dust...assuming it lives long enough to accumulate dust.
+1 on setting your own fanspeed curves with afterburner. Stock speeds are not conducive to mining or hard gaming. Also, make sure that the settings are applied across all similar cards, which is some box on the general tab in the settings. One of your fans is at 100 and the other is at 55...that ain't right.