The head gasket can leak oil from the front of the enginethrough the head gasket, it seals the front cover to the head also. The only oil there though is thrown from the chain. Are you sure it is oil? My 83 leaked what I thought was oil from the front also, it was black like oil, but after half an hour it evaporated. Oil doesn't do that! It was the gasket sealing the thermostat housing to the head, it leaked and ran down the engine takeing grease, dirt and oil with it turning it black. Easy fix, new gasket. Check around good, use a flaslight even in day light so you can see EVERYTHING! The front may leak also, only lower in the front.
Good Luck,
Joshua L.
Good Luck,
Joshua L.