I thought this was a regulator? A regulator should be mounted as close to the spraybar level as possible. If not the pressure to the spraybar will vary by the length from it. If the regulator is mounted well below the engine then the engine will run richer inverted, if well to the side then it could lean out when making high speed rolls. Another term for pressure is head, it is typically measured in feet, a 200 foot water tower will have a pressure of 200 feet of water at the bottom. So if you mount a pressure regulator 2 inches below the carb it will have a pressure head of -2 inch's of fuel in normal flight, but +2 inch's of fuel when inverted. Since the Cline regulator supplies fuel at a lower pressure, it is may be more critical about placement than the Perry Pump.