Timing is correct? Per what, the book that has to take emissions into consideration?

If an engine cranks for long periods of time, requires any throttle to start and run real fat, it's usually not enough initial timing.

I run stock 340-383-440's in the 14-18 range for initial and you'll never find a book setting that will suggest that much. They don't run fat, idle clean, start at the flick of the key.

Carb could be plugged up as well. Even if the carb was plugged up, primed, the engine should fire without any throttle.