I have 5" tall aluminum spun stacks on Borla throttle bodies.
They came out of one of the VW aftermarket shops.
They are from my 48ida's and had the extended skirts that extended into the carbs, like yours did. Those don't work with the throttle bodies.
As with yours, those needed to be removed,
What I did was simply machine 1/8" thick round aluminum flanges and aluminum solder them on to the stacks. Some call that aluminum welding, but it is more like soldering then welding. It is at a much lower temperature then welding is.
The flanges that I fabricated were drilled with two holes that match the mounting stud location and then at that point just bolted them on.
I was not convinced that silicone or using any kind of adhesive would be dependable, so I went the addition step.
When talking about screens, the flat screens tend to be restrictive. So you need to consider the coarseness of the fabric/mesh.
Also, even though you may find the best balance of filtering ability to air flow with a different mesh then I used, the more surface area that you can provide to them, the less restriction you will have.
This is a picture of what mine look like installed. The black bands you see are the "rubber o-rings" I used to retain the screens. The shape that you see of the screens is a result of increasing the surface area the most that was practical for me to reduce the restriction to air flow of the screens themselves.
The other thing that you need to consider is how are you going to protect the stacks from water. AT LEAST the last two are "out in the weather".
You may be thinking that, "I will never drive this car in the rain". OK, but are you going to wash it?
In my case, the increased height reduces the ability of the stacks to suck in water since they are within 3" or so of the bottom of the roof and also in my case, there is a clear Lexan shield (roof) extending over the stacks and made integral with my louvers.
You can't see the Lexan in this shot because it opens with the deck lid and the deck lid is up.
Remember, you cannot compress water and if you suck it in, you can bend the connecting rods and if you do. likely crack the cylinder walls.
I'm not posting in criticism of what you have done, just trying to give you more information for your solution and help it.
