Any reason you're doing the swap since you already have the pulley? What 'benefits' are you referring to? According to EC, the 64.7mm pulley makes more power/boost than even their 181mm crank pulley so if anything you're going to have a slower car with the 178mm while putting everything else in overdrive, I won't ever do a crank pulley either, I don't see any benefits to it over a supercharger pulley, only drawbacks.