piston rings

You mention an oil fouled plug.. as I mentioned in post #12.. (now I know why I'm tiring of this place)..

Is the oil accumulated on one side of the plug,, or generally evenly oil coated,, same for other plugs..

Oil accumulation on one side indicated bad valve guide, and/or seal..

Evenly coated with oil would indicate rings..

If you're thinking that replacing the intake manifold gskts may stop oil consumption,, that doesn't hold true on a /6..

The two manifolds don't need to be separated unless there's a leak in their mating gskt.

Definately de-glaze if you re-ring..

hope it helps.. cheers.