I posted this up on some of the other Lancer forums, so I figured that I would post up here, as well. Without getting into the whole balanced-unbalanced argument, this is for those people with 2013 model GTs who choose to install a lightened crank pulley. The timing chain cover has changed from the 2012 model to the 2013. There is a raised portion of the cover that will make contact with any of the aftermarket pulleys and will not allow the pulley to turn. I have talked with David at RRM and he has confirmed that their pulley will not fit until they have updated the design. So, if you have a 2013 GT, save your money on the pulley until the design has been updated. See pics of the chain cover below: