You cant unlock more pipes if thats what you mean. All the 9600 series have 4 + 2 vetex shaders. And the SEs have a 64 bit memory bus instead of the regular 9600/pro/XTs 128 bit bus. You cant change that.
My regular 9600 256 meg can clock to 450 core and 225 (450 DDR) memory, up from the stock 325/200 if you want to shoot for that. Might get hot though, I have a side fan that blows on mine. I use Omega drivers and ATITool to overclock.
XT speeds are 500 core 300 (600 DDR) mem.