GTXJackBauer
OP, your GPU configuration looks fine to me.  I think it's a contact issue.

When it comes to Serial vs. Parallel flow, with Serial, it's a bit more restrictive (forced to go through two GPU WBs) but the temps will differ higher between the two GPUs roughly in the 5c-10c range.  In Parallel configuration, both GPUs are getting the same flow on top of being less resistant but the temps might be slightly higher in general by a few degrees but the deltas between the two will be much closer as opposed to Serial config.




 
I personally use Serial only for pumps to combine the pumping power and use Parallel for GPUs for better flow and closer temps.

Here's a thread with similarities to your issue and the fix the user did.
 

RustyBrownEye
UPDATE
 
I think that pesky bracket is the culprit.
I realized that the TIM spread on the block was quite a bit smaller than the actual die when I pressed the block to the pcb with the bracket in place, and when I removed the bracket the spread was much better.
I decided to ditch the whole bracket all together and now my temps have settled at 55c instead of creeping into the 80s, which still seems a bit warm but that could be the terrible thermal paste evga provides.