I'm in the midst (was gonna put it on Saturday, but played slacker) of an attempt to put on an alternator from a '94 Pontiac Trans Sport, 140amp model.
I've had to do some custom bracket work to fit it, there's a special conversion plug from GM ($20) to switch from my '87 style plug to the newer one, and of course getting a bigger cable for the battery hookup.
The major problem I ran into was the A/C lines, and the main reason I didn't feel like f'n with it on Saturday. They are sort of out of the way, but the last test fit with the custom bracket, I didn't feel comfortable with the lines being that close to the alt. rotor, and they are a pain to move.
Cost of alternator? $170 from Autozone with a $70 core charge, so in the end it would be $100........