CR Specials don’t have sync ports. Race carbs are usually run at full throttle and very high rpms where a perfect sync isn’t a concern. A bench sync is more than enough for race carbs.
For my CR’s I added sync ports in the spigots I machined.
And I’ll say that that area in the circle is for the enrichening circuit. Not a choke per se as there’s no restriction that happens to the throat when the lever is pulled. Another circuit is opened to allow more fuel in.
