Here are the settings from my "base" configuration (before the broken fans on the 6950). The 7950 is GPU1 in this configuration (so it should be using the 2nd set of numbers).
"intensity" : "18,18",
"vectors" : "1,1",
"worksize" : "256,256",
"kernel" : "scrypt",
"lookup-gap" : "2",
"thread-concurrency" : "8192,22336",
"shaders" : "0,0",
"gpu-engine" : "900,1000",
"gpu-fan" : "90",
"gpu-memclock" : "1375,1400",
"gpu-memdiff" : "0,0",
"gpu-powertune" : "20,20",
"gpu-vddc" : "0.000,0.000",
"temp-cutoff" : "95,95",
"temp-overheat" : "85,85",
"temp-target" : "75,75",
"api-port" : "4028",
"expiry" : "120",
"failover-only" : true,
"gpu-dyninterval" : "7,7",
"gpu-platform" : "0,0",
"gpu-threads" : "2,2",
"log" : "5",
"no-pool-disable" : true,
"per-device-stats" : true,
"queue" : "1",
"scan-time" : "1",
"scrypt" : true,
"temp-hysteresis" : "3",
"shares" : "0",
"kernel-path" : "/usr/local/bin",
"no-submit-stale" : "true",
"verbose" : "false"
The only difference when the 6950 was out was the thread-concurrency
"thread-concurrency" : "22272",
Interestingly enough though, I put the 6950 back in without fans into the PCI riser slot. I had to turn all the settings for it down so it wouldn't overheat, and the 7950 with the exact same settings is now doing 530 kh/s. Strange...