Alternator HELP!!! (Long)

OK, Saturday, I was working on the car, couldn't get it to turn over. I had been up all night had it in first gear and tried to start it. Jumped a bit then would not turn over again. Had the battery recharged, but would not start again, but all the electrical systems in the car (idiot lights, radio, etc) worked fine. I found the wiring harness that runs from the starter to the alternator was horribly corroded (ie wire covering flaked off), so I rebuilt it using 10 ga wire and a couple of female connectors for the alternator and a loop connector for the starter bolt. As I was installing it (duh) I forgot to disconnect the negative battery loop. I'm underneath the car with my trusty 13mm ratchet I touched something metallic. Big spark, and now the car won't even turn over. I think I might have just discharged the battery.

Anyways, if I screwed up the alternator, I need to find out the size and type of lower bolt that hold the alternator on. I don't have AC and it bolts directly on the engine block. The upper bolt and bolt holding the track are 13mm, but I can't get the bottom one off trying to check the voltage regulator in the alternator...