It's true that the Comando had a larger single exhaust because it flowed better than duals. the engineers knew what they were doing. I have a friend that still drives his bought new '67 Barracuda Comando. He installed duals several years after he bought it but went back to the single exhaust because it gave much better perfomance and milage. The sound of the Comando exhaust is one of the coolest sounding exhausts ever.