You started this thread asking for info on changing valve seals. I assumed you were puffing out white smoke (oil issue), which could be the valve seals. Black smoke would be a fuel issue possible. The oil issue could foul the plugs, which then would seem like a fuel one. No white smoke, then your correct, look at the carb. If it is Holley, then there is your problem. LOLHey, so I been kinda bouncing between this and my other compression results threads. All the plugs looked trashed and it seems to be determined that the carb was leaking and fouling the plugs. I pumped the breaks on the valve seal for the time being and am working on new plugs, wires, & carb . .