piston rings
Where is the oil coming from.??
Looking at the deposits on the spark plugs should tell you if it's rings or hopefully valve guide seals.
Pull the plugs,, and if oil is accumulated on one side of the electrodes,, then its possible you just need valve guide seals..
Oil evenly coated on the plugs,, would indicate rings..
Google "how to read spark plugs"
A vacuum guage reading, along with the "green tab" samples at this link may also be helpful in determining your problem..
http://www.secondchancegarage.com/public/186.cfm
cheers..