Here's the correct pulley for the wide belt:

http://www.speedwaymotors.com/GM-Alternator-5-8-Inch-Wide-Belt-Pulley-Plain,1868.html

Do a copy/paste into your browser- - - -the link doesn't work for some reason. It's also available in chrome or aluminum, same page. This reference is for a steel pulley.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!