Why are these #'s critical for a good torque build? 

In this, episode 71, DV and crew chief Mervin Bonnet, reveal certain easily attainable combinations of parts can generate a stronger torques curve than others. This increased torque potential can amount to a sizable increase in lbs-ft per cube so it has the same effect as making your engine feel much bigger than it really is. Since all the moves described come about through increased efficiency you can expect greater fuel mileage as a plus.