Early A Body Dutra Duals

Just to throw a kink, dual exhaust is not always better. The early V-8 273 Hi-performance (Commando) engines came w/ a special exhaust, but it was a single tube. Apparently, they tested both and found the single tube performed better. In the 1970's, motorcycle magazines were full of ads for 4-into-1 exhausts claiming 30% more power. When Honda & Kawasaki changed to that in factory bikes, the same companies seamlessly switched to advertising 4 separate exhausts claiming 30% more power.