I am installing a new tile shower in our main bathroom. All framing and blocking has been done. I installed a new p-trap directly under the drain area. My question is this: Oatey drain came with my Goof-proof shower kit (pre-slope sticks, etc.). I am wondering if the drain goes flush with the 3/4" plywood subfloor, or if the nubs for the clamping bolts rest on top of the subfloor. I have seen conflicting diagrams on this point.