The screw definitely seems weird! Of course there’s no reasonable screwdriver that fits that head and is shorter than the bowl, it seems weird. Maybe a previous owner made a make-shift plug? Without it, of course there’s just a hole there, but it could help me troubleshoot. I’ll remove it tomorrow morning.
I didn’t wait long enough for the curb idle, but it still seemed to have a low level. With the need backed all the way off, the float never hits it, but the bowl didn’t overflow after ~3 minutes of idling. I am using the brass sight screw and I can’t even see any fuel. When I removed the bowl and dumped it out, there was hardly any fuel in there at all.
Great tip on the vacuum, I’ll look out for that. I haven’t ever dealt with timing before, so I have a lot of research to do. Just bought a timing light to read the RPM / set fast and curb idle. Excited to learn all about that once I get this carb dialed in!
Thanks again for your help, I’ll get back to it in the morning.