The baseplate of the 4010s have channels and vacuum passages that require you to install an adapter plate under the carb with most aftermarket manifolds. It's basically a thin plate shaped like the carb's bottom. Not a big deal but it does require an extra gasket. Many problems associated with this carb were due to vacuum leaks from the bottom gasket coming loose when the adapter plate isn't used.
Before Stangnet's big crash we had a few threads on the 4010 "farting noise" problem, which was the gasket failing and acting like a reed valve as it fluttered under high vacuum.
Before Stangnet's big crash we had a few threads on the 4010 "farting noise" problem, which was the gasket failing and acting like a reed valve as it fluttered under high vacuum.