Thanks Steve, it appears the thread is stripped, so I'm gonna have to tap it out. I started on the carb swap last night with @vfrer , had quite an interesting throttle linkage situation going on. It's a cable with 2 zip ties and an ounce or so of JBWeld. Gonna have to get creative to get it to work with the OEM carb. Needed two new gaskets though, so had to pause while I made some. Also working on something to cap the fuel return until I get that all hooked up and working again.Yes, the missing exhaust collector stud is critical. Get one, and the nut, and consider replacing the donut gasket sandwiched in there.
So we tested the idle solenoid and the wire it was connected to was getting juice. We then connected it right to the battery and it clicked on and off. Looks like it wasn't getting quite enough juice. I connected it to what I think is the old EGR connection and it worked! Clicked on and off when I turned the key to accessory and connected/disconnected the connection.
So this made it sound better, but still not great.
Next we tackled the timing with a timing light from "Sears Roebuck" that @vfrer got at a yard sale and I would bet is also a circa 1978. But it worked. Timing was pretty easy to adjust and helped, but the weird thing was that if we pushed down on the top of the dizzy or cap, it sounded like hell. I tightened the screw that keeps the dizzy from turning and that helped most of all. Then we drove it around the block and had a good NE IPA or two, reveling in our accomplishment.
I drove it to work today, first drive in over a month and it felt great! Excited to take it off road in a few weeks, assuming nothing breaks between now and then.