Attention: TDR Forum Junkies 
I'm sure you can get an older big rig air cleaner for cheap in a junk yard. Mount it in the bed, with a pipe going up the back of the cab. Most have a cyclone cap on them (about a foot across) that spins out large dirt particles and snow. It would not matter if they are oil bath filters or cartridge filters as the unit is plenty big enough to provide all the air our engines would need. The line from the air cleaner to the turbo could run under the cab near the exhaust.
Blake
Blake
