no air cleaner routing involved, I have the fabricated aluminum tall covers and had to drill both openings. Air cleaner is chromed type with fully exposed K&N element. No baffle or shield on the pcv side either, just the rubber grommet and pcv shoved in it. Friends have commented I'm sucking oil out of the valve cover at all times, then when no vacuum is present it would blow past. Such as in WOT.