Well folks I installed some plug wire spacers separating 7 & 8 cylinder wires by a good inch. I gave the right fuel/air mixture screw on my Edelbrock Performer carb a 1/3 clockwise turn to run just a pinch leaner on the 5-8 cylinder side. I spoke to Edelbrock folks who said that there might still be some blow back that might be causing slight oil or unburned fuel on some plug threads that may ease up as the engine is breaking in more. I will re torque the intake tomorrow and then go have some fun to see if anything is improving although it might take a little time to tell if blow back has anything to do with it.