I think anyone that has been around these cars long enough has had issues like this. I had an engine builder that had built several terrific engines for me really screw up a 408 Stroker for me. Never would get a good ring seal, blowing smoke, it almost hydrolocked from all the oil in the cylinders. Was a bad finish on the cylinder walls. So basic. I even took it back to the builder, so he did it again....still was not right. Finally, several aggravating months later, and removing the engine again, I had success from another builder. Cylinder wall finish was all that was really found wrong.