[T Bird]

John
From a theoretical perspective, I don't argue with you. The better the match between the port and the manifold, the better the situation. However, having seen how poorly most factory manifolds (exhaust and intake) match up to ports, 2mm doesn't appear to be much to be concerned with. As I said, that's an uneducated guess. Personally, I would rely on Richard Parr for a definitive answer, since he wrote the book on Weber carb applications for the 911 engine.