AFAIK the only Intel CPU's that have unlocked multipliers are the "K" models
There are also the "X" (extreme) models such as the i7-3960X.
Intel numbering SB-E in the 3xxx range irks me. They should have numbered those 2820/2930/2960. If they keep up this misleading numbering scheme, I'm guessing they're going to give IB-E 48xx/49xx numbers even though the rest of the 4xxx range will be associated with Haswell.