Some specs on JE Zetec pistons. These are available in 2 compression ratios. A regular Zetec is rated at 9.6:1. An SVT is rated at 10.2:1. The below information assumes a regular zetec, so INCREASE the rated compression by approx .5 point if you are installing this in an SVT engine.
JE 298715 - Bore 85mm, Dish. -8.0cc dish volume.