Originally Posted by Red_Stafford
What u mean by unlocked, overclockable?
Overclocking LGA1155 CPUs is done by increasing a multiplier which acts on the 100MHz base clock. Only i5 and i7 have adjustable clock speeds. Only the ones with a K in the end are fully unlocked (3570K, 3770K) i.e. they have no limit on the multiplier. All the rest, such as the i5-3470, can only raise the multiplier by four e.g. from 36 to 40 so you're limited to about 4GHz max.
Overclocking also requires a Z77 chipset board and an aftermarket cooler. I don't think the additional cost is worth it for you, just run a stock i5 on a B75 board.