I was wondering has anyone installed the Vishnu or go fast bits two piece underdrive/lightweight pullleys on the 06 or STI's? I called Vishnu and they said they dont recommend using the underdriven pulley on the 2.5 blocks b/c is messes with the resonance or whatever. Can anyone verify this? I guess I'll have to go with the standard lightweight pulley by perrin or GFB.