B/RB hardened valve seat insert size

[Kahill]

Does anyone know the specs on hardened seat inserts for B/RB big blocks or where to find that information.  I'm a CNC machinist and I can machine out the press fit seat pockets and the guides for concentricity, but I'm having a hard time finding info on the seat insert size. The Durabond website says .200 larger than the valve diameter.  I don't see enough room for this to fit properly.