One of the things I considered when troubleshooting a no-start was the vacuum lines. While this wouldn't really create a no-start, I was pretty much just grasping at straws. The existing vacuum lines were all rotted and gross. They weren't necessarily cracking or solidified yet, but I wanted to switch them out anyways. Unfortunately, whilst doing this I broke off a vacuum bung.
In terms of being cool, this was about the lowest on my list. I was devastated as the car was nearly there. This also meant taking the intake manifold off, which for me meant taking the engine out again. I took a break before doing this and gathered a second wind some weeks later. It turned out that pulling the engine was a great idea as the valves were bent. More to come on that.
Whilst I was stripping the paint off of the intake manifold for sandblasting and Cerakote, I decided to install the new bung. This entailed drilling the hole out and then tapping it for a 1/8 NPT threaded replacement bung.
I used a large amount of grease to hold as many of the metal shavings from falling into the hole. It worked very well. The intake manifold will be getting a thorough cleaning inside and out when finished but I wanted to take the extra precaution.
I did end up rounding off the bolt a little. Brass is way too soft for the tools that I had and the torque I was using. Either way, it doesn't leak! I tested with the old air and soapy water trick and not a single leak was found. I suspect the threads were firmly crossthreaded in there.