what is the pulley located almost directly under the alternator useed for? i threw a belt and just realized that its loose but i cant figure out how to tighten it

 

That's your AC pulley. the best and easiest way to install the belt (I've done it at least 200 million times) is to put it on all the pulleys except the balancer one, then when you go down with your 13 inch socket to the tentioner it'll be very easy to slide it on the harmonic balancer pulley while swinging the tentioner all the way down, and then when it's on inspect it with your eyes and finger and make sure it's setting right on all of them.
If you don't use your AC go to autozone and pay 39 bucks and order the AC by pass pulley, you'll take few heavy pounds off of your car, who needs an AC on a camaro with t tops except 57 year old lady who doesn't mind paying more gas on top of the 15 mpg in town ?

 

thanks for the advice , one more question the ac pulley itself is loose how do i tighten that, and btw i need ac it was 96 yesterday and its not even summer!!