Standard bore is 84.8mm and the ZS1/ZS2 pins are still 20.63 vs 20.00mm, not 19.00mm. Also I can't see the need for a decomp plate if used with a cvh head. Just don't spec an ultra thin head gasket. Also remember that the US zetec pistons will all have the valve cutouts for 16V.

edit: sorry for the typo