I want to replace the sights on my SP-01 Shadow with the CZC Adjustable Target Rear Sight and a Dawson Sight, for CZ SP-01 Pistols, Fiber Optic Front. The rear sight calls for an 8.5mm tall front sight. Is that 8.5mm the height of the front post or the height of the whole sight from the bottom of the dovetail to the top of the post? Which Dawson height would be right?