The hole in the end of the induction air snorkel where it mates up to the fuel injection servo was oval rather than round, and it wasn't in the centre of the mounting flange (picture before). Many other builders were complaining about the fit of this piece, so there didn't seem to be any point to having Van's send a new part.

Last week I added a bunch of fibreglas in all the right places, and then used a Kutzall carving burr to round out the hole. I spent quite a bit of effort to make sure to get a smooth, large radius on every corner to try to avoid creating turbulence.