-Just thought I would let you know that you may get away with this, but the tapers on the Shimano bb is diffeent than the Campy cranks. You will ruin the cranks by forcing the different tapers or maybe better put, you will distroy the the Campy milling so if you go back to a Cmpy bb you will have a sloppy fit.
Bottom brackets are inexpensive enough to do it right.