Look, If your trying to remove the carbs from the intake, then get a 1/2" line wrench and disconnect the rear carb from the brass "T" Block that connects the center and rear carb. Then remove the intermediate carb line (between the front and center carb "T" Blocks at the brass "T" Block to the center carb.
Doing this will allow you to remove the carbs. Start by removing the rear carb, then the front and last the center.
This will allow you to replace the lines you want to and get them tight on the "S" lines with trial and error fitting before final assembly to the intake with carbs and lines.
If you try to remove the lines at the carb bowls with them installed on the car you'll end up with leaks unless you "custom grind" some clearance on the outside of your line wrenchs, so they will fit into the tight squeeze with the carbs installed on the intake.
Hope this helps.
Bogusracer