Okay, well I dont know what pulley this is, but I am having a heck of time with it. I bought one of those allen wrench things that are built onto a 3/8 socket (its a 8mm). I put a 3/8 socket extension in place between the pulley and the block so that the pulley wont turn when I try to loosen it. However, I am putting a LOT of torque on this thing....and it isnt moving. I dont want to snap the damn thing! Its really holding up my install at this point cause I dont know what to do and I have to remove the timing cover. If anyone has any tips please let me know cause I am clueless on this one and couldnt find any info when searching.