didnt someone else here do dual exhaust already i remember ready about how they got the plastic trim from mitsubishi to make it look factory and i love the blance of the look from the rear
not 100% on it, but if they were un equal you would get a different sound due to length. its all to do with the pressure the exhaust is plus the bends and lenght and atmospheric pressure.
i hope it doesnt sound poo...if it does. throw in a X-pipe
my old 300zx has dual pipes totally independant of each other off the engine. and seriously the best exhaust ive had on a car. it wasnt very loud, but it had a deep sound u could feel. if anything, un equal exhausts would give a rex exhaust note.