Does a drag race only car need exhaust boxes?

Your countryman David Vizard has an excellent section on exh systems in his small block Chev book, SA books #57. Well worth getting. He also explodes the myth about having equal length pri pipes. There is a dyno test in his big block book, equal v un-equal, with unequal making up to 29 HP more [ & never less hp ] on a 525 ci engine