Paul and all, this thread inspired me to do more digging on the system on my car. One tube says IMCO 2.75… so I am guessing that my setup was built by a shop using IMCO chambered tubes. So I can’t comment on the sound of the Gardner system or GM NOS but I can tell you that this system built from IMCO components sounds fantastic. My car had a major restoration from 2000-2010 in the Chicago area (the owner of Foreign & Domestic Auto Body in Libertyville) so I’m guessing this system was built around then
