I gotta correct you a little here. Dynomax Super Turbos (the oval ones) are not "very restrictive." They are the best turbo muffler on the market IMO, with large diameter internal flow tubes, & flow directors at each end of the muffler. As far as Hooker Aero Chambers, I remember Rick Ehrenberg using these on the 360 Valiant One Lap of America car & he said they were so loud, they had to stop along the way & install glasspacks in the tail pipes just so they could complete the circuit.