Run this
cgminer --scrypt -o stratum+tcp://stratum.wemineftc.com:4444 -u maursader.1 -p x --intensity 13 --worksize 256 --thread-concurrency 8192 -g 2 --gpu-engine 1051 --gpu-memclock 1722 --auto-fan
That memclock is crazy. I'm at 1100 core and 1320 mem and getting around 710kh/s.
Put your powertune to 5% at least in cgminer.
Also take out GPU_USE_SYNC (never seen that before) and --gpu-fan (it's redundant since you already have --auto-fan).
Put your thread-concurrency down to 8192 and see how it goes.