Like I always say, "Everybody's got their own THANG."
I remember 'tuning' the sound for sixes, by moving the mufflers closer to the engine for that raspy rap/rap, or far to the rear, for a deeper, rumbling tone. You really can adjust the sound by moving the mufflers forward, or rearward.
I first saw a welder 'tune' the sound on a big ol' 308 ci Hudson-powered 2WD Jeep pickup in the '50s.
With dual headers and pipes, that sucker had a 'bad' rumble to it! If I remember right, it had 2 International tractor mufflers on it!
