318 intakes - old style?

what you need is a dyno for ants!

(but in all seriousness, maybe you could glean some information from fuel consumption data)
I doubt it. In fact I’d bet (within the useful range of the dyno) you could make two pulls and not even notice there were two graphs. Using the same engine and two different stock cast iron 2 barrel intakes. They’ll make the same power so they’ll use the same amount of fuel.