BBD big bore 2 barrel carb help

That really is not a rare carb, but they aren't around much anymore. One of the issues that carb has is the air cleaner stud is threaded into the air horn instead of the main body. If the air cleaner nut is tightened too far it will distort the air horn and cause idle issues as well as choke blade opening issues. Another issue many of those big cars had is blowing the cap off the fitting on the brake booster.