The Bizzarini 5300 GT has the Chevrolet 327 l76 small block. In some versions it has the 4 barrel holley and it looks like the regular l76 327 from chevrolets of the day but when they put 4 Weber DCOE sidedraft carburettors this part circled in green was also put on there and i cant understand what that part is and what it is supposed to do. There are 2 shafts inside it with gear teeth but i have no idea what they do. Would be very nice if somebody knows what they are and could explain
This appears to be part of the throttle linkage. Considering you have four 2-barrel carbs which oppose each other, you need some way to synchronize all four of them so when you step on single throttle pedal, you actuate all four at the same time. The mechanical nature of this is to push in two different directions at the same time. This ensures each carb opens and closes at the same time, at the same rate. I'm sure it also provides adjustability as well as some sort of throttle stop, both on the top end (wide open throttle) and to allow for a minimal air flow (for idle purposes).
This seems like a very fanciful way of doing it, as I've seen other methods of just providing cables which are ran through a series of pulleys to let it actuate at the correct angles. I would consider this method very over-engineered, but it still gets the job done. Some engineer decided it was needed.