Absolute newbie here. I have a stutter as soon as I hit the throttle. I did a vacuum test from the little hose in the carb. These are my readings. It actually seems like it runs better without it connected to the vacuum advance. Less of a stutter but still not gone. What would y’all do next?
Check the PCV valve for movement, remove and clean with solvent, if needed.
How do the spark plugs look? Fouled?
Early ignition systems are just fine. Points can be serviced just like spark plugs can be gapped. If their service is too inconvenient, it might be time to rethink time, space, and other resources going into the project; after 50-years it is considered an antique, not exactly equipment for luxury or convenience. Also, carbs without 'ported' vacuum are not necessarily going to be responsible for engine stutter.
Other service would be rebuilding the carb for corrosion and varnish. Fuel injector cleaner might be good preventative maintenance, keeping varnish from forming in the carb and restricting fuel flow - it is like the solvent soak part of the carburetor rebuild, but without disassembly.
I think that the lack of throttle response with a
cold carb and intake manifold is kinda normal on these engines. Fuel-atomization issues such as cold temps, and a non-laminar intake charge flow from the carb to the intake head ports can 'paint' the internal surfaces with the bigger fuel droplets, leaning-out the Air/Fuel ratio in the intake, temporarily. Also, if you look at the top of typical intake valves, they are all caked-up with polymerized, and / or ashed oil deposits - again fuel injector cleaner can help the engine breathe easier, and, leaky valve stem seals can be replaced. If the stumble is present on a warm motor, it is probably something you can address.