I am running cgminer 3.1.1

this is my bat file configuration
================================================================
cgminer --scrypt -o http://yourltcminingpool.com:port -u Username -p 1234 -I 13 -g 2 --thread-concurrency 8192 --lookup-gap 2 -w 256
================================================================
my clocks for the first card (645 KH/s) = 950/1500 (I played around the clock speed to get 645 KH/s... it was lower when at 1044/ 1500)

My clocks for the second card (735 KH/s) = 1044/1500

About  0.63 to 0.69 ratio, but that works for me your is different probably.

Where I found those clocks speed.

https://forum.litecoin.net/index.php?topic=2507.0

Also I am running 2 Powercolor V3 7970