Removal of the tube requires a tool that will thread into the tube with enough strength to pull the tube out. In many cases deposits lock the tube in place and that is the reason the the nut is removed leaving the tube in place. There is a special removing tool in the Carter Carburetor Tool Kit. They are extremely difficult to find. Some of us that rebuild those carbs have the tools.
You can try to use a #3 wood screw. It will thread into the center of the tube but may not pull the tube if it is "glued" in place by deposits. Hopefully the end of the tube will not break or split trying to get it apart. If you decide to try to drill it out then be extremely careful as the tube must be "gas tight" in the lower passage and seat into the upper passage.
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How Sweet the roar of a Chevy four!