I don't have the intake so can't speak directly to it, but I've seen this mentioned before -- I read a review from someone a while back that said he had issues with his rubbing. I contacted S&B to see if they had any other reports before I decided to purchase and was told it was an "isolated incident." Then a month or so ago I saw a used one come up for sale that appeared to have rub marks on top of the tube.
There does seem to be some tight tolerances in their design.