So, I got the lights figured out on my 68 Firebird. Just an FYI, the lights in the back are 1157's, NOT 2057's that were in there. THe 1157's are a tad brighter as well

The tail lights all work, and the directional signals work. However, the brake lights don't work. I'm trying to troubleshoot. I just found a pic on this website for the fuse panel. That's gonna help me out a bunch. But if the turn signals and taillights work, then it "should" be the brake light switch, correct? I'm trying to run this down. There was only one wire connected to the switch. THere was a 2nd terminal on the switch that had nothing attached. There was a stripped wire with no terminal end on it tucked up under there. However, there's no power to either wire. So I'm gonna trace from the fusebox to the switch itself.

Sounds like you're on the right track. The directionals are on one circuit and the brake/emergency flasher on another. Look for a white wire. Mine was caught under the steering column.

I just did a complete wiring harness on my 68. The brake light switch has one power wire (orange I think) that comes from the fuse block that connects to one terminal. The other terminal at the switch has two wires, one is feed to brake lights and one is feed from turn signal switch. Turn signal wire was white/some other color (can't remember). Hope this helps.