If you buy a new pulley it should have a new tooth ring attatched to it. Need a good place and deal, I got the pulley and belt shipped for 190 from Redline Performance Mustangs, www.rpm-mustangs.com
Ahhh, then i have no idea, but I'm guessing they are not quite the same, otherwise why would a new one come with one when you could just swap them over?