2mm will make the different already. More air to go in to the air chamber and combusion room. That's why some bore it until 64 or 67mm... After market TB like Jun is 70mm at inner diameter. But bigger doesn't mean better, big enough for ur engine OK lar. Don't tell me a stock b16a is going to put a 67mm or 70mm TB.
A fellow Skyline owner asked me if there was a gathering coming soon. I didn't know how to answer him. It's almost the middle of 2010 and perhaps it's about time we organized a gathering for the year.