I've cleaned the engine a couple of times to make sure I've got all the usual leaks fixed (we got this car, 66 mustang, 200 ci. c4 about 18 months ago. going thru 1st level engine, suspension and steering upgrades. noticed yesterday that it looks like a small amount of oil is seeping out between the head and the block, replaced the valve cover gasket and this leaks starts much lower than that. compression test a few weeks ago was, 135, 135, 155, 155, 160, 155. don't have the vehicle history so I don't know when it was rebuilt. does have a fair repaint from some time ago. someone suggested that the difference in compression could be a head gasket problem, have others had oil seep this way from a bad head gasket? odometer has around 70K miles, I can't believe this is an untouched engine, the usual minor rust around the rear quarters, a tad on the roof line. lots of orange peel. engine does have some evidence of having been repainted (blue), that's all stripped off where the oil leaks out. thank you.