Using a single 7970 2.7 ghs i hit 2 blocks today.
Solo mining has always been more fun to me.
 
Here are my settings for a 7970


cgminer.exe -o http://127.0.0.1:8984 -u username -p password --blake256 --shaders 2048 --gpuengine 1175 --gpumemclock 700 --thread-concurrency 22392 -w 264 -s 1 -E 1 -I 15

if your system can handle it push the clock speed faster than 1175

it seems to provide no performance boost with intensity at 15

these are not going to work on a 7950 but hopefully give you some reference material.