I have searched high and low for an aftermarket air intake with zero luck. I need to get this thing breathing better, any advice welcome. 2005 g3500 passenger.

 

No available 'kits' I found in my quest to turn my pig into something approaching economical.

Pulled the airbox 'nozzle', installed 'woodpecker wire' to catch anything bee sized or larger & then installed a Spectre oiled air filter from ebay (like a K&N oiled filter). No appreciable improvement but then again my pedal foot is heavier than others.