Originally Posted by lt1silverhawk
Should the test have been done with the carb on?
Carb off is fine.
Yes, the oil is actually limited to just the threads of the spark plugs. The electrodes and porcelain don't have anything on them and, from memory and the pictures posted, there was no dis-coloration
That's good, the oil leak is external and there's no need to fret any more about the rings, valve seals, PCV, or intake gaskets. Be sure to go back and retighten the intake a few times after it heat cycles until the bolts take a set.
You'll want to locate the oil leak that's getting into the plug recesses. It could be coming from the front of the engine and blowing back from the fan. It helps to have the engine clean. Another thing you can do that will sometimes help locate a leak is to put a piece of cardboard under the engine after running it. See where the drips are concentrated and look up- and possibly forward- from the heaviest spots.
Now, where I am needing more help is how to see the position of the electrode in relation to the exhaust valve. Will I need to removed the intake manifold and turn the engine manually to observe what's happening? The plugs are out right now, and in order.
No need to remove anything. What you want to see is if the plug electrode/porcelene are fouled or discolored more on one side of the electrode than the other. If they are, the next thing will be to determine what valve the fouled side is facing. The valve sequence on a SBC is:
I I ³
E E ⁵
I I ⁷
E. A spark plug will sit where every numeral is. So looking at the sequence, you can see if the plug for cylinder #1 has more deposits on the left side when it's fully tightened into the head, that the deposits are coming from the exhaust guide.
If there is no "worse" side to the plugs and they look to be coloring equally, that's good and nothing need be done.
One thing about the vacuum advance- be sure to reattach the vacuum hose to it after setting the timing. When an engine pings, it'll sound like a faint metallic ticking. Some describe it as marbles in a can- but the detonation would need to be pretty severe for it to be that bad, IMHO. You'll notice it more when you load the engine in a higher gear, like going up an incline or hill.