The taper doesn't have to be extreme, it just helps keep air velocity from stalling. Again, look at any factory EFI intake design. Many that you see are the result of millions of dollars of R&D testing, and will provide an excellent comparison. This will eliminate having to try and go off in a tangent to create one for yourself. The Ford 300 EFI intake is an excellent comparison because it is near identical cubic inch, and they did what Chevy never did do, and that is they actually made one from the factory. Starting from scratch for a new design though, its helpful to have a 3D modeling software package that can do stress analysis and air flow analysis like I have, it will save hundreds of hours in chasing dead ends and will help get you on track the first time out.
