below is a picture of the Buick I used to have, and the first cold-air set-up I had on it. I had two vents from the fenders of a Trans Am mounted into the hood to resemble the Buick GS hoods. On the carb was a kit that I bought, but that could be home made easily. It was a metal rectangle, close in size to a McDonalds tray, with a hole in the center to fit tightly on the carb. It was held in place by a Weiand foam triangle air cleaner (open element across the top). Along the edges was a piece of 1" thick foam that sat 3 or 4 inches tall, and sealed against the hood. This worked excellent until it rained. I eventually bought a fiberglass Cobrajet Mustang hood scoop, cut a hole in the hood that was 1/2" wider that the circumference of my Moroso air cleaner, and then boxed the forward end, creating almost a keyhole shape. Then I mounted the scoop over the hole (the air cleaner rose through the hood about 2 inches). There are even better ways to do it, but I ended up getting rid of the Buick (521 horsepower wasn't enough for a 4400 pound car).
Take care,
-Chris