Educate me on Alternators

[n33k0]

Greetings, gentlemen.

I'd appreciate some help trying to figure out what alternator I need for my truck. I took the old alternator to the local autoparts store to test it and they confirmed it was dead. I figured I'd just get a replacement of the same alternator while at the store but we couldn't find any part number on the unit, just "Delphi Automotive Systems" on the side with the pulley. The guy behind the counter asked for the truck info to look up the part number I needed, but the alternator that came up in the results didn't look like the one I have now, it had a V belt pulley while my truck has a serpentine belt. It's a 350 SBC, not many accessories other than an aftermarket radio powering two small speakers behind the seat. The alternator has two connections: a plastic clip with 3 or 4 metal pins (but only one wire coming out of it) on the side, and one heavier gauge wire attached to a threaded rod on the back of the alternator. I'm not sure where the wires are going, tracing them would require pulling apart all the wire looms the previous owner used to organize the engine bay. I don't know much about alternators, and I'm a bit overwhelmed trying to pick the right one for my truck. I'd appreciate any help you guys can offer.