Underhood aero...worth it?

[J-440]

Evening all. I have a 68 Dodge Charger which is not the most aerodynamic car in the world but I'm improving it otherwise. Am looking to get more airflow from under the hood and I wanna run this by ya'll. I already have a glass 3 1/2" cowl hood with heat extractors from a '14 Mustang that work well. What I'm looking to do is fab a thin sheet of aluminum covering the huge gap (looking down at the car with the hood open) from the edge of the grill to the radiator. It's about a 5 1/2" gap in the middle then tapers on both sides to about an 1" towards each fender.
By covering this "V" what aero gains would I see? Or would this be total overkill for an 80% street car? I also like the look of overhead fender louvers like you see on newer Vipers and Porsches to get the air out of the wheelwell. Thanks again.