That’s a vacuum governed Holley 2 bbl carb but that’s not the correct distributor

 

The air cleaner's original 7/16" double-ended stud has been cut off and a smaller bolt brazed on (probably 1/4-20) for that later air cleaner. IDK why they didn't just drill out the hole in the lid instead. And, with no air cleaner gasket to the carb air horn, dirt just bypasses anyway, so why bother?