SBC Head flow

I am trying to figure out whether there is a way to gain added low rpm torque with aftermarket heads. I am studying:

http://chevyhiperformance.com/techar...98/index4.html

What I don't understand is that the stock 882 heads flow as well as the Dart Iron Eagle heads although the intake passage is smaller (151 cc) compared to the Iron Eagle intake passage of 165 cc. To get the same (almost the same) flow at say 0.400" intake valve lift, the gas velocity would have to be higher in the smaller passages and that should lead to more low rpm torque while the larger intake passages should support more horsepower at higher rpm. Maybe the 882 heads DO give more torque at say 2200 rpm but the dyno charts seldom show below 2500 rpm? Of course the obvious thing to expect would be that the Iron Eagle heads would give more H.P. at say 4500 rpm, but the question is whether the 882 heads are actually better at 2200 rpm where I will be cruising with a 2.79:1 rear gear. There is no sense paying for aftermarket heads when I have a set of freshly rebuilt 882 heads, so the question is whether the Iron Eagle 165 or other aftermarket heads give better torque in the 2000-2500 range or are the 882s really better in that rpm range?

Don Shillady
Retired Scientiist/teen rodder