Unless my MAFs are different than other stock MAFs I dont see how anyone could run more air through these 2.75" boost tubes with them in their stock location.
BBRSpeedworks put me onto these which takes advantage of the laminar flow in the boost tube and the fact that the friction along the sides of the tube actually slow down the incoming air and thus allow you to read higher flow values with the stock MAF by moving it out closer to the edge of the boost tube.
Hitachi Slot Style MAF Mass Air Flow Adapter Flange, FORD and GM- TREADSTONE PERFORMANCE