Custom duals to y pipe

Several years ago there was a discussion on fordsix.com on how to run your exhaust system. A system was described that involved running intermediate pipes all the way back to axle into a resonator box. This was attributed to David Vizard. A gent built such a system for his '64 Falcon, using a flow master muffler as the resonator box. Claims were made of improved low end torque. There is video on YouTube of the car and exhaust system. Were the claims true? I don't know. No before or after dyno slips, so maybe the butt-o-meter was wrong.

I do know that when I extended my intermediate pipes about 6", it messed up the jetting in the carb. Which means it was flowing more air thru the engine. Just my observation.