Intake mod?

A dual plane has a better signal to the carb because the carb is effectively cut in half in terms of how the engine "sucks". However that tends to mean that oeak torque will be reached earlier (lower) in the rpm range and that horsepower will drop off earlier. By using an open spacer, or cutting the divider down, you can play with that signal and "fool" the engine into carrying the peaks further. It's a mod that was done mostly back in the 70s and 80s before better intakes existed. It usually has little or no down side at all, so if you have it, no biggie. If your intake is unmodified, I'd say choose the intake that best fits your application and don't worry about it. I'ev never done it myself but I have ran them before (usually a swap meet intake type deal). I do not believe any of the Edelbrocks are not cut from the factory but I could be wrong there.