get the Motorcraft (Ford) 3G..
http://www.oldengine.org/unfaq/3ag/3ag.htmwreaking yard they run around $20 - 30...
Reman around $70 + -
New $$$
pull one from a 3.8 V6 need to get a V pulley for it if you don't have one
and you might need to put a spacer behind it...
I did this swap on my 351c years ago, and just now doing it on my
56 Packard...
I used the pulley of the 2g, but had to make a spacer, to get the pulley off
the Alt body I got a washer with a 5\8 hole, then ground it down to fit the
recess that the pulley fits down into. You will not be able to use the normal
lock washer. Also the upper mounting bolt I think is metric so if you get one
from the junk yard, take both bolts... you can figure out the rest
OH and get one with 180 deg opposed ears, they come in 3 configurations.
Best