Never remove the linkage from the outboards and run the car. If they open there will be no closing them. This linkage closes the carbs, the vacuum lines open them.
With engine off remove the return springs to the center carb and hold it wide open. Now open the outboards by hand and see if the operate smoothly and easily. They should, they’re will be a mild resistance from the springs inside the vacuum pods.
Easy way to tell, go run the car wide open for 5 seconds. Now un plug the vacuum hoses from the outboards and do the same run, is the car running slower now?
to add to Dana’s post, if you have to ask, they are not opening!