62mm versus 63mm bored out TB

I am looking at getting a bored out TB. I am looking at either one by Leigh or one by thefastman. One is 62mm and the other is 63mm and I can't say that I can think of any reason in reality why that 1 mm would make a difference. Anyone have an opinion on this one? any ideas would be helpful.

It wont make a difference.

IIRC the whole in the intake manifold is only 62mm so there would be no point of getting a throttle body that is 63mm.

That is unless you decide to port out the manifold, but for 1mm its worthless. If you had a 68mm throttle body and port matched that then it'd be worth it, but only with a higher performance engine.