650 Ti - What can I overclock to?

What do you recommend for an overclock? 

 

http://pcpartpicker.com/p/T3ev

 

That is my build, for a reference.

I just need to know because overclocking is free performance.

Overclock the core to around 1100 mhz and overclock the memory to 1600 mhz. This should be stable all day on stock voltage.