I'm having the same problem with my '46, 216. It won't start cold unless I spin it with a jump from a 12 volt. I think my problem is a combination of things like weak spark from dirty coil conections and maybe timing not advanced enough. I cleaned the electrical connections and put in new plugs. That's helped it start easier and run without a miss.
Have you tried a 12 volt jump? Make sure you're getting fuel to the carb. Pull the air cleaner and see if fuel squirts into the carb when you work the throttle linkage back & fourth if you haven't yet.
Jacques
