68mm at plate and 70mm at base. If you look closely there is a ridge that extends out from the base out to 75mm or 76mm which is probably that max I would have it bored out IF it can be that big in the first place just so the air doesn’t hit the edge of the. If it really can be bored out that big then it would have more potential then the 3.7 TL throttle body a lot of people have put on to accords and older TLs which could be bored out to 72-73mm.