So I have a small block 350. Rebuild on the motor has been maybe 1000 miles ago. I've been having issues with cylinder 6 and 8 fouling the plugs put and when I pull them it looks to have burned/seared oil on them. I'm trying to get most likely ideas from the people as to what the problem could be. This is cylinder 8 plug. My carb is tuned well, idle at 14 afr, cruise at 13 afr, wot at 12.5 or so. This plug was put in yesterday. The car was run street and highway for maybe 45 minutes so that's how long this plug has operated. Hit me with some knowledge please so I can get it sorted out.