Just wanted to share this problem with you all. I just recently tore my 383 apart. It first started with it needing cam bearings then as long as the block was at the machine shop I decided to have the block cleaned and put new bearings all around. The crank was polished and the bores were honed(new rings were installed . Pistons were cleaned along with the block . I assembled my "new " motor . Then when I checked my plugs one of them was fouling up with oil . I was getting nervous thinking my rings had not seated maybe worse. Well, I calmed down and started checking the smallest things first. I checked and installed new plugs , I installed new plug wires, I installed a hotter plug on the problem cylinder, checked the ignition system(module, coil ,cap and rotor),I checked compression(which was good), then as I was about to take the motor out of my Camaro to tear it down I decided to take the intake out before taking the entire engine out. That is when I found my problem . The intake gasket was leaking oil . There was oil all over the head port (which was the problem cylinder). I was so happy it turned out to be the intake gasket and not anything more serious. Why am I telling you this? Cuz it's goes to show you not to overreact and check the small things first! It's not like I did not know intake leaks can get the plugs oily. I just assumed the worst. Shame on me.