I’ve heard the rumor too about that “dimple” . I’m not certain but that it may be cast into the base when it was made. I discussed that rumor with Bill Overcash when I first started using him to restore the carbs on my Superbird. He never found it necessary to drill out that dimple. Neither have I had any problems and I’ve been messing with six packs since 76. After Bill passed last year, I decided to start restoring carbs. So far, I’ve taken apart about 30 end carbs and have no problems getting them out if I’m careful. Carbs in better overall condition are easier. The old corroded carbs take more care. I get the gasket out and soak it with carb cleaner and/or wd40, but I’m still very careful. I have gotten them out on several that customers have sent into me already broken off. If you do break one off, give me a shout. I bought all of Bill stuff so I have some spare ones.