No, the base clock on the locked chips do not overclock much at all. On non-K chips, you'd be lucky to get 100-200mhz over stock.
The base clock on 1155 chips is 100, the 2600k is 3.4ghz so the multi should be 34. I'm not sure if turbo works the same as socket 1156, if it does the multi can be as high as 38. But like I said, the base clock can only overclock like 3-5mhz so 105x38 is ~4ghz.
Why not spend the extra $25 and get the K chip? Then you'll be able to overclock to atleast 4.6-4.8ghz most likely very easily.