I'm getting 340 Kh/s  with sgminer using the following script:

"intensity" : "21",
"worksize" : "256",
"kernel" : "ckolivas",
"lookup-gap" : "2",
"thread-concurrency" : "5864",
"gpu-engine" : "0-800",
"gpu-fan" : "0-85",
"gpu-memclock" : "1150",
"gpu-memdiff" : "0",
"gpu-powertune" : "0",
"gpu-vddc" : "0.000",
"gpu-dyninterval" : "7",
"gpu-platform" : "0",

I would like to try the new kernels that comes with sgminer, but it looks like you need to retune the thread-concurrency