Just out of curiosity, but if you are willing to fab this up, why not just fab up a snorkel? I remember seing one somewhere online made with PVC pipe and a cookie can to put around a cone filter, and it looked quite nice... This way (1) the intake air will be colder (taken from a higher point, where it is less affected by the temp of the road, as well as coming from outside the engine bay), and (2) you will have less risk of hycrolocking the engine on the mud/water holes.