yea, probably did look kinda funny... with flows, blowing or putting air to it, it felt like you were blowing through an empty box almost, glasspacks or turbos had a little restriction to it. The air didn't have the same velocity coming out the back of the muffler.
I had A muffler on my old 72 with a 200 6 . It was called a turbo pack looked like a glass pack but had the low growl of a turbo .And it was pretty loud.
actually i've heard a i6 sound like a v8.... maybe it was the old man glasspacks that made it sound funny ... btw whats a glasspack?
A few years ago a friend gave me a whole chart of flow tests done at !5" pressure: 2.5" straight pipe was 521 CFM 2.5" Hooker Aero Chamber was 324 CFM 2.5" Dynomax Super Turbo was 268 CFM 2.5" 2 chamber Flowmaster was 249 CFM 2.5" 3 chamber Flowmaster was 229 CFM