Quote:

If it isn't in the boundry layer there is no positive pressure at the carb.



I believe you meant to say ABOVE the boundary layer.

I've always had a mini-airo scoop with a K&N flat panel filter mounted in it's base and it has always been a predictable car. One reason for the filter is to keep junk out of the engine but I also did it to stabilize the air above the carburetor. IMO, if you just have a hole with a scoop above it you're gambling in the unpredictable and often counter intuitive world of compressible fluid mechanics. My filter might cost a little top end speed but I'm a bracket racer not an ET chaser.

The shape of the air stream above the hood likely has many influencing factors such as the length of the hood, angle of attack, and the shape of the nose of the car before the hood. Trying to find a solution that works in all cases is most likely a lost cause.
My new plan is to go back to a stock hood (in glass) and take air from the nose of the car on both sides of the radiator. I'll also install air deflectors behind the grill to try and generate some additional pressure. As it is, I have around 2" from the top of the carburetor to the underside of the hood. Since the venturis are 1-13/16" (with annular boosters plugging them up) I figure the air should be fairly lazy making the bend and it will have the full 360 degrees available.
I wouldn't put a cowl hood on anything. Those things look totally 'High School' to me.