I've done some reading about underdrive pulleys and heard that running and under driven crank/eccentric pulley and water pump pulley is most effective and that an underdriving alt pulley defeats the purpose of underdriven pulleys..any experiences/facts on this..thanks for your time

 

unless your car is a track only car, and you are doing an AC delete, there is no point to pullies unless you want some 'bling' in your engine bay.