I used a Weiend filter like that on my Z/28. They are cheap, have a good sized piece of 'foam' in them, and in general are pretty flexible to work with. Since it's a simple piece of stamped steel
screwing and riveting custom pieces to it is easy. You could easily rivet a piece of 1/16th thick or so aluminum to the bottom of it to give you some meat to put some sort of foam seal around it so it got all of it's air from outside the engine cover, rather than sucking it warm engine compartment air.
I stuck mine down in the base of the huge factory aircleaner holder assembly. It was a tight fit but I convinced it to get down in there... then I used a strip of 2x8 inch foam, about 4 feet long around the edges of the big GM aircleaner holder, to seal it to the hood.... That way the Weiand airfilter was pretty much forced to get all it's air from the Z's hoodscoop. (I'd made that non-functional scoop functional with a craftsman sabresaw!)
My setup was 'sort' of like this, foam around the outside that sealed to the hood, and the Weiand aircleaner in the middle attached to the carb instead of this 442's trapdoor setup.
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It totally cured my vaporlock problem, sounded AWESOME and added something like 300hp to my buttdyno. Seriously, I can't stress how killer it sounded. Then I wrapped it around a pole in a parking lot in a solo car crash, like all Camaro and Firebirds are expected to be wrecked.
