Yeah, it's more like 63mm, just measured it...did you have to machine the manifold to "port match" the TB? 63mm to 70mm seems like a lotta meat to take off, and it seals with an o-ring type gasket, maybe cutting into the slot it sits in. Or did you just go to a flat gasket? Or did you not machine it at all? If not, seems like that "step" would cause flow issues.