When making a change like that it is a good idea to check the full throttle MAP and IAT sensor readings before and then after. Temperature affects the power more than pressure changes.

Years ago I made a U tube manometer out of clear vinyl tubing and at full throttle and 4000 rpm on a1995 Ram Magnum 5.9 V8 measured 4 inches of water restriction ahead of the air cleaner element. This was the restriction from the passenger side fender inlet, through the corrugated plastic hose and into the air filter housing but ahead of the paper filter element.

If I remember right the total restriction measured by the MAP sensor was 1.6 inches of Mercury, which converts to 21.8 inches of water.

If I remember right the legendary Chrysler engineer Tom Hoover removed a headlight and by taking in air there got the inlet restriction down to zero. At 80 mph it climbed to +1 inch water.

Forward facing inlets like this would clog your air filter with bugs and debris kicked up by the road traffic.

Those big 18 wheel trucks that take in engine inlet air way up high get cooler air.
Air near the pavement is hotter, as this I75 weather station shows.

http://rwis.kytc.ky.gov/071/graph1.htm