Wow you just reminded me of a Commando experience here in CO. One of my good friends from the time who still has a 66 Dart Convt Charger 273 had a 65 Formula S that was special ordered by an Air Force Academy grad (Class of 65) whose first assignment to Panama was changed to Vietnam. His (Air Force) blue Cuda with factory A/C was sold on delivery and stayed in CO. That first registered owner got a noise citation from Boulder police for his stock exhaust, I remember seeing the ticket in the mid 90's. The 65 273 4/bbl had no muffler at all except for the straight thru resonator at the very tip and was very loud, practically an 8 cylinder Harley. In 66 Mopar added the central unbaffled muffler which was enough to quiet them down. If you've never heard a genuine original 65 you've missed something, kind of like the 69 Chevy chambered exhaust systems. Anyway, a freeflowing single exhaust, particularly as output from a high compression engine is a unique sound and I encourage you to play with that.