Nikola, when I built HB's -A version, I had the same problem with the intake. I decided that trying to fix it might cause more problems than it would solve. I left mine as it is. Sorry that I don't have a solution to offer. Still, I'd like to build another HB A-7, so I'm curious to see if you come up with a solution that I might be able to use in the future.
Good luck!
-O