360 Aluminum Manifold, eBay Knock Off on Edelbrock?

[1970FuryConv]

360. Open plenum or divided...the efi does not really care as its not dependant on vacuum, I "heared" that too but i think its more like "heresay" ya know.... i think its more that where a carb might have issues, the efi works better. Open plenum needs a massively enlarged pumpshot, even just with an open spacer I noticed that, Im just wondering if performance and/or milage could be increased by that air gap intake .

On performance, once the engine reaches operating temperature, if the intake and carb are cooler, this is supposed to increase density of air/fuel mixture, therefore increasing performance because a large volume of fuel enters the combustion chamber.
Air gap is one method of keeping the air/fuel mix cooler at operating temperature by isolating the intake runners from engine heat.
Another way of keeping the air/fuel mix cooler at operating temperature is to use a phenolic spacer below the carb to isolate the carb from intake manifold heat.
Can't speak to mph