What are the optimal cgminer settings for a AMD Radeon HD 6670? I'm following this tutorial for mining Litecoins, and I'm having a little hard time finding the optimal cgminer settings for my AMD Radeon HD 6670. Any hint on that?

The tutorial gives this configurations for Radeon 7950 series GPUs (which is not mine):

timeout /t 30
setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
cgminer --scrypt -I 19 --thread-concurrency 21712 -o stratum+tcp://coinotron.com:3334 -u [USER] -p [PASS]
So far I have been using

-I 18 -g 1 -w 256 --thread-concurrency 2400

Getting ~71k/h with clock at 820 and mem at 852

I hope this helps