Try 960 core (1.05v), about 400mh/s. Temp was almost 80C, decreased to 68-71C (fan @ 80%) after a dose of Prolima Tech PK-1. Room temp is about 34-35C during the day, definitely much better than it used to be with 5 cards.

I used to run the cards at 775 core (0.85v) at 330mh/s when BTC price was less than $15.