I have 1/2 thick radiused lexan inlet plates that I use for every head that I flow so that isn't an issue. Almost every head is tested with an intake mounted as my Friends that I do work for are usually there to see the before and after numbers of not only the head but also with the intake bolted on. Each and every head and sometimes every port are checked for air-speed throughout the port which will show you exactly where the issue is and what needs done to correct the problem. They could and should be checking this too but its all about the "bottom line" for them and many others.