I know the gains are minimal, at best. That video was a stock engine, stock exhaust, stock 1bbl intake with a slew of fuel delivery options thrown on.
Safe to say, if done right, better breathing can result in good low end, just need the right items and mods to make it work.
On my particular rig, the 4.11 gears, multiplied by 0.73, equals 3.00. 3.00 is my overdrive/final drive ratio, which is in the low 2k rpm range.
