The E63 suggests it's the 383, but looking up Plymouth Fury for the year your wagon was built, numerous engine options were available. The forum experts should be able to advise you how to tell what you have. Possibly the air cleaner was replaced with the one you have??? Anything could have happened during the last 47 years.
In 1972 the 400 replaced the 383 so unless its a really early build it does not have a 383.