A 273 Hi-Po single exhaust system will out perform a dual exhaust system in most cases. A low and mid-range torque increase has been realized when switching from duals to the original style Hi-Po exhaust system. The original Chrysler engineers did their homework on this one. Accurate LTD did their homework by improving the original Chrysler design by incorporating an improved scavenger y-pipe design and smooth pipe bends. All this and it fits like a glove.