I just returned from 2 weeks in Asia (China, Japan, Korea). Japan was awesome.
Anyway, spent a couple hrs on the truck today. Got it running after confirming wiring was correct, 12v everywhere it was needed, then:
a) plugging all the vacuum hoses and ports. It wanted to turn over, but didn't start until I,
b) turned the dist cap as advanced as it would go.
Once running, it sounded normal, all 8 cylinders. If I dialed back the timing by turning the dist cap, it would back fire a little, so I left it as advanced as I could with the cap position.
I hooked up the timing light and it appears ~12 degrees ahead of 0. But the weird thing is the timing light was not flashing steady, the light seemed to skip some revolutions. This is making me wonder if spark is actually travelling to Cyl #1 on every revolution, or if there's an issue with the distributor. You can see this action in the video.
So, next steps are:
a) reconnect one vacuum line at a time and see if/which line is causing a leak.
b) remove the dist cap for inspection/replacement.
Overall, I'm happy it's running again even though there are a couple bugs to work out.
https://youtu.be/uSN6lzK4BdA