Take a look at my CAI I made. I took the stock peice from a TPI camaro and plumbed it into a normal aircleaner. I'm using a smaller element to allow air from the top to enter as well.
As you can I had to add weatherstripping at the back because of the way the hood molds.

 

Here's how the air enters from the top.
There are two metal plates that go over top. I shimmed them so there is a 1/4 clearance from the hood.
You can't tell the hood is altered at all when I put the plates in
I'm going to cut the whole thing out except for the mounting holes for the plates to allow more air from the top.

 

I'm impressed. Any problems in the rain, though?

 

I'd like to do that with my TPI aircleaner too but I havent found a compatible carb air cleaner that would hook up easily to the TPI one. What did you use ??

 

I'm using an old air cleaner off a 6.2L diesel pickup my dad had.
The cleaner is 16", my element is 14". I'm going to get a k&n top filter, that chrome is gay.

I think they use those same aircleaners on the old 454 trucks also.

Water gets in when I wash the car, If I spray right onto the vents.
rain hasn't found it's way in yet.

 

I considered that, too. Looking at your pictures, I'm glad I didn't try it. My AC lines go from driver's to passenger side on the top of the radiator support. Since two objects can't occupy the same space at the same time...