Also don't try cut and paste what other are doing for overclocking! Every chip is different and overclocking on sli means your clocks will be limited with the weaker card.
Most important thing is to get the fan curve up from default to cool that top card better.
These pascal cards use boost 3.0 and will boost on loads (free auto oveclocking) and lower when 3 things are met. Voltage limit,power limit and temp limit. Your big one right now is temp.
At 52c it will lower then again at 62c and 70 and so forth to keep it stable.
People want 2000-2100mhz..
Every chip is different and every room and case have different temperatures to deal with.