diameter to a stock NA waterpump pulley? I thought that the NA version was larger than a TT version, and in my case I am running the NA pulley on my TT engine now. I only ask because if the NA pulley is about the same size as this OD pulley... I would think I would already be counteracting the underdriven effect of the UDP on the waterpump.
Just throwing it out there. If I'm way off... anyone feel free to show me the light.