Seems to me (after some research) that for the 1969 9561 COPO, one really had only 2 choices of exhaust systems. Either the Chambered Dual Exhaust or the Deep Tone Dual Exhaust with a single muffler in front of the trunk. Ordering a dual exhaust with dual resinators does seem to have been an option. Is this true, or am I just making this up?