Engines with lack bottom end power?

MopaR&D said
Tuning is important but especially if it's a carb'd application, air speed and booster signal at lower RPMs are crucial. They are directly related to how responsive an engine is under light throttle. Also when larger amounts of valve overlap come into play the tuning of the exhaust can make a huge difference in torque below the peak RPM. Lots of tests showing how collector extensions on open headers give a massive improvement in torque and the longer they get the lower the RPMs where torque is increased.

I agree with everything but the effects on torque and not say your wrong just having a hard time seeing torque being the issue. Cause take the 5 built 318 282-477 hp they all make more bottom end than a stock 360, not saying a stock 360 is a power house but wouldn't be considered soft under 3000 rpm, take a fairly built 383-440 people will say they have a soft bottom end but are making similar to lot more down low torque than a strong running 360.

So is there a torque number eg.. like 350 lbs-ft around 2000-2500 rpm?, which most smaller engines would fail and most larger would pass, or at least a minimum lbs-ft per cid, I just don't think were talking bottom end torque when saying a built engine are soft down low. A built six and 543 are gonna make vastly different amounts of torque either can have a soft or strong bottom end for what they are.

Sofar to me it's mainly the cam don't like to operate down low.