And FYI, EGR stands for "exhaust gas recirculation" and only Broncos starting in '73 had them.
It's a good thing, but one more thing that people like to remove because it's part of the "dreaded and reviled smog control stuff" and many get tossed into the trash.
So if your Bronco did not have one, then you would use the manifold for use "without EGR" for best results.
If your engine is equipped with one (I don't have a picture, but it's a disc-shaped thingy just behind the carburetor on later model engines) and you want it to be able to pass local smog inspections, or open it up to a wider audience for sale, then you would use the EGR-specific intake manifold.
Paul