Are you sure it's the box? If a lot of play, where is it coming from? Should not be the box if it is newer like you say. Unless it was mis-adjusted from whoever built it. We've actually seen that many times, so maybe a few checks are in order.
But no, I don't believe the 4x4x2 box will improve your feel over a stock 4-turn box.
Is yours an early 6-turn box, or a later ('76-'77) box? If a 6-turn then yes, you will feel a difference, but whether it's felt as an improvement or not will be the question.
If anything, the new Delphi boxes would theoretically have the advantage. But as I have not spent much time comparing them all from the driver's seats, my opinions are just barely supported.
Paul