oil leaks in the proximity of the fan can be  hard to track down.  

On  Dodge pickups,  that's where the vacuum pump/power steering pump   bolts to.     It's  always a mess in that area.   Either the vacuum pump leaks,  or  power steering.   

Seeing a new gasket didn't  fix it..  I'm thinking the  cover-to-block  gasket or  seal is   suspect.      Some apps  use a gasket,  some  only RTV. 

Start by  pulling the compressor off,  and  see if that  new gasket  has  stayed  dry,  or  is   wet  with oil.  If  dry,   keep  going!!   the timing cover to block  seal is  probably  the  culprit.  (look at the compressor  closely,  it may be the problem)