I would start out the same size and go bigger say to about 2mm Bigger. You really dont need to worry too much about the anti-revision bit because most TBs have this built in. Look closely. You will see it.
Its only about .5mm. On most of the Honda TBs I have seen.
I saw a post of yours and I believe you are the person, to ask.
So have a d16y8 intake manifold(56mm tb and opening), which is stated, as good enough, for a humble, builds, like mine. I'm coupling it with 60mm throttle body. I found a lot of people, saying, that the IM opening, should be 2mm bigger, than the TB, because, they say, it's to prevent reversion of air flow. As stock they are with the same bore - 56mm.
My question is, should I port match TB and IM, or go bigger(how much) with the IM?
P.S. The engine is d15z6(=d16y5) - vtec-e. My setup is quite simple, for the moment - big K&N cone, CAI, 4-2-1 aftermarket with thermo band, EGR - blind gasket, IACV & TB heating, removed.
Thank you for the help