Ford Repair: timming, valve cover gasket, mustang 6 cylinder

Question
I have a 1999 mustang 6 cylinder convertable.The car has about 50,000 miles.I have did all the tune ups every 3 thousand miles but last month i poped open the hood and i can see a littel bit of oil comming from the head gasket.its not much but it drips about two drops of oil a day,and the oil is comming from the back sid of the block.i know my mustang is a fat hog but its my only transpertation to the base.When i changed my spark plugs last week there was oil around the top buy the threads .it wasnt alot of oil but everyone had alittel bit of oil around the top edge of it ,could this mean that my head gasket is going out?and if it is do you know how to set the timming because there doesnt seem to be a rotor cap to adjust the timming,just a littel box where the plugs come out.im used to older cars not the newer cars so if you could give me some advice i would greatly appreciate it.I have also check my oil and my antifrez and neither is contaminated.The car doesnt run ruff at all and the car doesnt overheat.thank you.
v/r oracio

Answer
Hello and thanks for the question...I'll try to help.
 Are you positive that it is the head gasket and not the valve cover gasket that it is leaking? The 6 cylinder's usually don't leak oil from the heads. Also, the ignition timing is NON-adjustable.
Hope this helps,
Erik