FWIW,
The diameter of the tubes in headers will determine the rpm that peak torque occurs. Larger tubes higher rpm smaller tubes lower rpm.
The length of the tube will rock the torque curve around the peak. Longer tubes will enhance torque below the peak, shorter above.
Longer collectors will enhance low rpm torque. Larger diameter collectors will enhance torque above the peak.
The primary advantage of a block hugger over manifolds is the reduced flow restrictions. You won't get much in the way of a scavaging effect until you are way up in the rpm range. Full length headers will give the reduced restriction but you will also get significant scavaging and will produce more torque through the entire rpm range compared to the block hugger.