Peaking is tricky business. If there is no impending meet, then peak different lifts at different times. The logical approach would be to peak your bench half way through your squat/DL cycle (and vice versa). This way you are under less total stress and assuring that optimal amounts of rest and recovery are had.
When you have an upcoming meet you should peak all at the same time for obvious reasons. One will surely take from the other but that is the game you play. I believe westside says to end your cycle two weeks before the contest and use the next week for gpp/recovery. This sounds much like what I do and it works very well.