How does a hood scoop work?

OK. The Hemi scoop was designed as a race only unit. No baffles, no nothing. They did not race in the rain.

You could start with a fresh air-type filter housing, such as from an Air Grabber Roadrunner or GTX (I believe they are being re-popped again). This unit would have the thick foam rubber band that seals the base plate to the hood-mounted mating plate.

Or, you could fabricate something from an old giant base plate from a C-body. The question remains whether you want ram air effect. If you do, you will have to "box in" the filter unit to the hood so that all incoming air goes to the filter/carb and not mix with hot underhood air, which, by the way, is somewhat pressurized under speed. This was not a concern with race cars because they got to effective ram air speed fairly quickly, which overwhelmed the under hood pressure.

On a street car with the Hemi scoop, because of the huge opening of the scoop, not only will you scoop falling rain, but water on the hood will be pushed into the opening. Look at how water travels along your present hood in a rain storm to get the idea. If you want to use the Hemi scoop on a street car, you might want to create a curb on the hood around the hood cut-out to direct water away from the hole and through vents on the side lower edges of the scoop.

For street driving, if you want to do minimal fabrication, go with the snorkel. At least you won't have the water running into the engine compartment from the hood deck.

Just my opinion and some ideas to work with.