My friend got this alternator for his 91 TBI Firebird looks to be Serpentine belt setup, it was never used, stored inside and my Firebird doesn't need it... so rather that have it take up space, it's for sale.... May fit other GM models of that era, a pic of the number on the alternator is posted too. Did take it down to the autoparts store for testing, passed & the guy even said, "looks brand new!".

$50 shipped in US via USPS

Pics here...

http://tampa.craigslist.org/pnl/pts/2047105296.html