I watched the guys install my tops (full 40mm tops), the carcases where made with points of strength due to the thicker granite. the holes where cut with an angle grinder (outside), the resulting joints where filled with a resin and dried as hard as the top. We have an overhang at the breakfast bar (approx) 300mm and two big Islander fellas did the install. they where very particular with getting it level, they had little wedges of different colors which where of differing angles. A bonding stuff was put down in small dollops on the top edge of the cabinets and it was set in place. To me it is a specialized install, do it wrong it will be expensive.