Just got this 68 C30, questions

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Newbie here, thanks for your patience. I've worked on and owned many vehicles but never a Chevy besides a 95 van, 20-series. I'll start out with the background and get to the questions.

Bought this truck from a friend who never used it... he had loaded it up for a dump run and then left it alone for a year or two. I drove it home in the pictured condition today after putting a different carburetor on it and bypassing the old gas in the tank (the ol' tie a can of gas under the hood and carry a fire extinguisher trick...). Spent the rest of the day getting rid of the junk and washing the truck, didn't take after photos yet. I do landscape installations for a living and am preparing to restore my log-cabin house here in Asheville, so I'm definitely looking at this beast as more of a tractor/workhorse than a classic or looker, but that said if it works well I'd love to get the body right at a future point in time and make er pretty. Right now I just need it to haul though. And I'm sure it will once I get some kinks worked out, that first gear is about right for pulling oak stumps...

The I6 engine is supposedly a 250 out of a later Chevy. The ~68 monojet that I put on it has two vacuum fittings - one for the distributor, and the other? To the fitting on the coolant line at end of valve cover and then to the exhaust gas device? If so, which goes on top and which on bottom? The carb I took off had 4 vacuum fittings, but they were all plugged besides the distributor line. Pics to follow.

The truck had some major wiring issues (the harness that goes under the steering column was nearly melted in two...) and did not charge the battery while running. Instead of troubleshooting everything I'm just starting from scratch - I've removed most of the old wiring intact and begun installing this http://www.ebay.com/itm/Universal-GM...-/131579061374 It seems straightforward, but I'm a little confused about wiring the alternator (or generator, how do I tell the difference by looking?). It has a new external voltage regulator similar to the one on this camaro forum http://www.camaros.net/techref/elect..._regulator.htm
but my question is, the wiring kit comes with an "alternator excitor" wire. Should this be connected to the brown wire on the voltage regulator?

Also, brake lights... glad I had my friend follow me home. What is the connection on the bottom of the master cylinder where the brake lines are distributed? I assume it must be the brake light switch since I don't see one anywhere else but I fully don't understand how it works.

Thanks a bunch, more photos soon and plenty more questions.