What positions should the intake cam lobe be at top dead center when installing the top chain?

HOW DO YOU GET THE IDLER PULLER TO THE PRPOER MARK? WHEN INSTALLING THE TOP TIMING CHAIN ; THE TIMING MARK ON THE IDELER PULLEY FOR THE TOP CHAIN, TO ALIGN THE CAM SPROCKETS? HOW DO YOU GET THE IDLER PULLER TO THE PRPOER MARK? WHEN INSTALLING THE TOP TIMING CHAIN ; THE TIMING MARK ON THE IDELER PULLEY FOR THE TOP CHAIN, TO ALIGN THE CAM SPROCKETS?