If you are curious enough just try it. Used to be a fad around here when I was a kid some guys would run one stock muffler and one glass pack, I guess the object was it was not quite as loud, dunno, lol. I am sure the flow wasn't equal, but if you use a crossover, X or H pipe, whats the big deal?
Rick Kilpatrick, AAS Automotive Systems Tech, Alamance Community College, Class of 99. 06 5 speed manual Mustang with Pony pkg : GT Mac Mufflers, true duals with one custom pipe. 2.5" system. GT bumper cover, all installed March 7&8 2006. AFE Stage 1 CAI, Motoblue Underdrive pulley, GT aluminum shifter knob, honeycomb rear blackout panel,and dash kit installed. Roush hood scoop and side window louvers installed. SS taillight trim has been installed, new alum. GT steering wheel installed.