Actually, it would be better to say, the intake runners are tuned to provide a slight super-charging effect within a specified RPM range. Longer runners typically bump up the bottom end while shorter runners feed the top better. The resonant tunning I believe can be affected by runner taper, but is for the most part independant of the actual runner cross-section. The same with runner volume except for the effect it has on velocity.
As for plenum volume, larger or longer plenums give the A/F mix more room to negotiate the turn into the runners and provide a larger volume of A/F to pull from.
Typically you would want the a runnner with the minimum crossection with the right length so that it provides maximum cylinder filling in conjunction with the cam. (impossible to do with most carb intakes, single plenum short runner carb intakes such as the Vic Jr. provide little or no tuning benefit at all other than connecting the air valve to the cylinder heads (well that is to say that the resonant tuning is so high as to not be practical in most applications.).
Ideally the intake, cylinder heads, and exhaust are matched up to provide superior cylinder filling with-in a specified rpm range, which creates a great engine with kewl peak HP and TQ elements, however the intake and exhaust can be manipulated so that they provide differing torque peaks which can be used to broaden or narrow the engines powerband.
I suppose the best situtation would be to provide the broadest possible range in which max (or nearly so) volumetric efficiency would occur over the widest rpm range.
All this is academic for most of us since we don't have the resources to whip up a custom intake for every engine we build nor the money to sit at a dyno swapping cams, heads or exhaust until internal combustion nirvana is achieved
My advice would be to contact the intake manufacturer (I've called Edelbrock's tech guys before they seemed pretty nice)