Repeated oil fouling of spark plug #1

[CharlesAFerg]

Repeated oil fouling of spark plug #1

What would cause this? Leaky valves? Valve guide seals?

[Tiger]

Valve guide seal is first suspect... sometime the valve guide get loose and then that would mean the valve guide too.

[632 Regal]

Try a hotter plug for now. If at any time your thermostat was stuck open it could have caused extensive ring cylinder wear. The intake valve guides can do it too as mentioned. You could try to replace them while still on the car, not absolutely hard to do.