Hi I have a 1990 LX 5.0 with the Ford Motorsport Underdrive pullies. I wanna upgrade my Alternator to a 130 amp. Will the alt. work with the underdrive pulley? A tech from Powermaster said that the underdrive pulley has to be smaller than the stock pulley I took off. Is this true or does anyone know if the underdrive alt pulley is smaller than stock?