Well Dave, even though you have the ability, it would be better if you just pull the engine and send it off to get professionally rebuilt. It would take a book to walk you through assembly of the engine. Tearing it apart is not a real problem. What will be the key to dependibility is the machine work and proper assembly. Torque values, clearances, assembly procedures, pre-starting, measuring the old parts (oil pump, crank, etc.) and on and on will make or break the engine.
Sounds to me like the rings are shot in #8? No way would that much oil from one or two guides foul a plug that fast. It's for sure a combination of ring sealing alone with the guides is my guess?
No, a valve adjument being out of spec is not a cause for oil fouling. It's a matter of worn parts....meaning, ring and/or guide wear.
I keep bring up my simple theory about parts that wear out on each other. Rub both hands together. Which hand stayed cold? You see, when one wears against another part, they both wearing out almost equally. Different metals being a variable, the principal remains the same. So if you change guides, for sure, change the valves also.
Let's try to narrow it down a little. Let me ask you a few questions. When you first start the engine cold, do you see a puff of smoke out the exhaust? My next question is, if you get the engine up to running temperature, and pull the breather tube off the valve cover, can you see smoke bellowing out the hole? Get back to me on this and let's see if you can get away with pulling the heads only and having new valves/guides installed without removing the engine for another season. At least you'll have a little mechanical experience by removing and replacing your own heads on the engine block. If you have to rebuild the block, you already have the heads done and you can just send out the block for crank and piston work. Always replace the oil pump on a new engine.
