The length of the metal threads at the end of a spark plug is called the "reach".
it must have threads and create spark
Either the spark plug needs to be tightened or the threads have been stripped out. Also the rings are shot to allow that much oil into the combustion chamber.
Could be that the threads are stripped on the plug or the head where the plug is screwed in. Or maybe it's the wrong plug..
if the oil is at the spark plug base the valve cover gasket is leaking. if the spark plug electrode is covered with oil the engine needs rings
The threads in the head may be dirty. Try cleaning them out with a round wire brush. If that does not work, try a different plug. If another spark plug will not tighten, then the threads in the head are damaged and you need them professionally repaired.
A small bit of oil, if on the firing end or at the initial threads is acceptable, but may indicate wear along the rings or head gasket. Oil in the area above the crush washer and threads (where the plug wire is connected) could indicate that the plug was not in tightly enough, or that your valve cover gasket needs to be replaced.
If your spark plug doesn't screw in your threads might be messed up. Run down to your local Part store and ask for a Thread Chasser($arround 10$) and screw that in to your spark plug housing just as you where screwing in a spark plug. What this does is it replaces the threads. Take out the chasser, Lubricate your spark plug and you should be good to go.
No there should not be any oil where you plug your spark plugs into
You might try to use krol as this oil can creep into the smallest cracks to help loosen the spark plug. http://www.kanolabs.com/ The next problem will be the threads probably will be stripped. Use a Time-Sert insert to repair the stripped threads. http://www.timesert.com/html/sparkplug.html http://www.timesert.com Good luck!
A 1968 Ford Galaxie 500 with a 390 engine should use a spark plug such as an E3 brand spark plug. This plug should have a tapered seat with 18mm threads.
no