alternator pulley/ dyno

i have a 1996 z24 does anyone have any dyno sheets for any cav and how much does this alteranator pulley actully do is it worth the money?

Im new to the cavy world, Alternator Pulley can someone inform me??

Im new to the cavy world, Alternator Pulley can someone inform me??

maybe im missing something here but from what i know, its the round piece of metal that goes in between your alternator shaft and your serpentine belt,
as far as buying one, everyone ive ever had to deal with came new with the new/rebuilt alternator