'66 Barracuda starts then dies right away

Probably close enough. I'd put the key in RUN and make sure you have voltage at the end of that blue/white wire, the one that comes out of the connector to the ballast resistor, if no voltage try wiggling the wire at the bulkhead connector. If you get juice there, it's a bad connector. If not, probe the contact at the bulkhead connector at that wire's slot for voltage, both under the hood and the dash. If you've got juice under the dash but not under the hood, again bad connection at the bulkhead connector. If you want to confirm the car will run once you track this down, run a jumper from the + batter terminal to the + terminal on the coil. Should start and run no matter what. Its probably time for me to mention that I in no way shape or form are an expert at electrical stuff, I hate it as much as the next guy and know even less. This one, though I spend months tracking down myself before I figured out that help was available.

Never the less, I appreciate the help. That's why I love this board so much. So full disclosure now, I went back out, rechecked my upgrade work and pulled on some bulkhead wires etc. It started up and stayed running for about 5 minutes until I shut it down. I think it may be either a loose connection/bad wire or a fuel issue as well.

I will say I am becoming much more competent with my electrical work. Thank goodness these cars are pretty simple. If I could get all the correct wire colors I would probably rewire everything. May end up doing that circuit by circuit over the long haul anyway.

I have an LD4B waiting in the wings and will be getting a 4bbl carb to go with soon. It's never run very smooth so...on with the saga of 50+ year old cars and wiring.