Overclocking Intel Core 2 duo E7500 ?

I have core 2 duo E7500 , asus P5KPL AM/PS motherboard , 2gb DDR2 ram , i changed AI in BIOS to OVERCLOCK profile , it is set at 20% , CPU speed is 3.2 GHZ (originally 2.93 Ghz) , FSB = 1288 MHZ , DRAM frequency = 667 Mhz , CPU ratio = 10 , all the memory over voltages, 1.25 over voltage , Vcore voltage are set to auto profile , what more can i do ?