Does a drag race only car need exhaust boxes?

As above, gonna have to tune for open or muffled. How well a cutout works depends on where it is. Closer to the headers is better. See enginemasters cutout episode.
Most times if an a collector extension (directly off the header) isn't used, midrange torque will be hurt, sometimes dramatically. I have no idea if they work off of a cutout.
I have always raced with mufflers, and our local strips (supposedly) require them . I don't believe a properly sized and free-flowing exhaust hurts performance much, if at all.