FYI....prod engine pickup inlets are normally 1/4"-3/8" off the floor of the pan. Some of you likely know this, some may not. This is not for difficulty in suction if too close to the floor nor trying to stay away from sucking up any debris in the pan, although both are helped by the space. The real reason for prod engines is water. Yep, plain old water due to condensation. Engines can build up quite a bit of water in the pan during cold operation, and obviously aggravated by winter temps. Upwards of 10% or higher of water concentration in the oil. The only way to get the water out is for the oil to reach the boiling temp...which is hard to do in the wintertime. Since oil floats on water, the water will be settled to the bottom of the pan when the car is shut off and all the oil drains back down to the pan. Then on a startup, you'd like NOT to suck all that water into your engine! Also, the water can (and will!) freeze...then you have ice in or blocking the pickup with no ability to suck oil. So physics being what they are, water will be on the bottom so you give the pickup some space to the floor of the pan to 1) prevent ice on startup blocking the pickup and 2) prevent sucking pure water on startup if it's not frozen. As for why the pickup is typically on the bottom side of the pickup and parallel to the floor of the pan, it really just comes down to oil sloshing/starvation. You want to to keep the pickup covered at all times. High G maneuvers (typically turning or braking are higher G than acceleration in most newer cars!) can send the oil away from the pickup tube so the best chance to keep it covered and minimize sucking air is to have the pickup on the bottom side. Everything's a compromise!